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  • 1.
    Abdollahzadeh, Makan
    et al.
    K.N.Toosi University of Technology, Faculty of Geodesy and Geomatic Engineering, Tehran, Iran.
    Eshagh, Mehdi
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Geodesy.
    Najafi, Mehdi
    K.N.Toosi University of Technology, Faculty of Geodesy and Geomatic Engineering, Tehran, Iran.
    A semi-vectorization algorithm to synthesis of gravitational anomaly quantities on the Earth's surface2009Conference paper (Refereed)
    Abstract [en]

    The Earth’s gravitational potential can be expressed by the well-known spherical harmonic expansion. The computationaltime of summing up this expansion is an important practical issue which can be reduced by an efficientnumerical algorithm. This paper proposes such a method for block-wise synthesizing the anomaly quantities onthe Earth surface using vectorization.Fully-vectorization means transformation of the summations to the simple matrix and vector products. It is not apractical for the matrices with large dimensions. Here a semi-vectorization algorithm is proposed to avoid workingwith large vectors and matrices. It speeds up the computations by using one loop for the summation either ondegrees or on orders. The former is a good option to synthesize the anomaly quantities on the Earth surfaceconsidering a digital elevation model (DEM). This approach is more efficient than the two-step method whichcomputes the quantities on the reference ellipsoid and continues them upward to the Earth surface. The algorithmhas been coded in MATLAB which synthesizes a global grid of 50 x 50 (corresponding 9 million points) of gravityanomaly or geoid height using a geopotential model to degree 360 in 10000 seconds by an ordinary computer with2G RAM.

  • 2.
    Abrate, Matteo
    et al.
    CNR Natl Res Council, Inst Informat & Telemat, I-56124 Pisa, Italy.
    Bacciu, Clara
    CNR Natl Res Council, Inst Informat & Telemat, I-56124 Pisa, Italy.
    Hast, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Visual Information and Interaction. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction. CNR Natl Res Council, Inst Informat & Telemat, I-56124 Pisa, Italy.
    Marchetti, Andrea
    CNR Natl Res Council, Inst Informat & Telemat, I-56124 Pisa, Italy.
    Minutoli, Salvatore
    CNR Natl Res Council, Inst Informat & Telemat, I-56124 Pisa, Italy.
    Tesconi, Maurizio
    CNR Natl Res Council, Inst Informat & Telemat, I-56124 Pisa, Italy.
    Geomemories - A Platform for Visualizing Historical, Environmental and Geospatial Changes of the Italian Landscape2013In: ISPRS International Journal of Geo-Information. Special issue: Geospatial Monitoring and Modelling of Environmental Change, ISSN 2220-9964, Vol. 2, no 2, p. 432-455Article in journal (Refereed)
    Abstract [en]

    The GeoMemories project aims at publishing on the Web and digitally preserving historical aerial photographs that are currently stored in physical form within the archives of the Aerofototeca Nazionale in Rome. We describe a system, available at http://www.geomemories.org, that lets users visualize the evolution of the Italian landscape throughout the last century. The Web portal allows comparison of recent satellite imagery with several layers of historical maps, obtained from the aerial photos through a complex workflow that merges them together. We present several case studies carried out in collaboration with geologists, historians and archaeologists, that illustrate the great potential of our system in different research fields. Experiments and advances in image processing technologies are envisaged as a key factor in solving the inherent issue of vast amounts of manual work, from georeferencing to mosaicking to analysis.

  • 3.
    Abshirini, Ehsan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013). KTH, Geoinformatik.
    Koch, Daniel
    KTH, Arkitektur.
    Rivers as integration devices in cities2016In: City, Territory and Architecture, E-ISSN 2195-2701, Vol. 3, no 1, p. 1-21Article in journal (Refereed)
    Abstract [en]

    Background: As dynamic systems rivers and cities have been in interaction under changing relations over time, and the morphology of many cities has risen through a long and steady struggle between the city functions and the river system flowing inside. This makes river cities an interesting case to study how the presence of geographical features interacts with spatial morphology in the formation of cities.

    Methods: The basis of this research is enabled by utilizing a novel model for cross-city comparison presented by Hillier in his Santiago keynote in 2012 called a “star model”. This is done on large samples of cities investigating concurrent configurations, as well as how the properties in this star model react to specific forms of disturbance.

    Results: Results illustrate that the foreground network as identified through maximum choice values in cities are more vital to the structure of cities than the bridges. The overall syntactic structure tends to retain its character (degree of distributedness) and the location of its foreground network (which street segments constitute the foreground network) even when bridges are targeted. Furthermore, counter to the initial hypothesis, river cities tend to change less than non-river cities after targeted disturbance of the systems. Finally, the results show that while there is a statistical morphological difference between river cities and non-river cities, this difference is not directly explained through the bridges.

    Conclusion: Integrating space syntax with statistical and geospatial analysis can throw light on the way in which the properties of city networks and urban structure reflect the relative effect of rivers on the morphology of river cities. The paper, finally, contributes through offering one piece of a better perception of the structure of river-cities that can support strategies of river-cities interaction as well as enhance our knowledge on the constraints and limits to that interaction.

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  • 4.
    Abshirini, Ehsan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Koch, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Rivers as integration devices in cities2016In: City, Territory and Architecture, E-ISSN 2195-2701, Vol. 3, no 1, p. 1-21Article in journal (Refereed)
    Abstract [en]

    Background: As dynamic systems rivers and cities have been in interaction under changing relations over time, and the morphology of many cities has risen through a long and steady struggle between the city functions and the river system flowing inside. This makes river cities an interesting case to study how the presence of geographical features interacts with spatial morphology in the formation of cities.

    Methods: The basis of this research is enabled by utilizing a novel model for cross-city comparison presented by Hillier in his Santiago keynote in 2012 called a “star model”. This is done on large samples of cities investigating concurrent configurations, as well as how the properties in this star model react to specific forms of disturbance.

    Results: Results illustrate that the foreground network as identified through maximum choice values in cities are more vital to the structure of cities than the bridges. The overall syntactic structure tends to retain its character (degree of distributedness) and the location of its foreground network (which street segments constitute the foreground network) even when bridges are targeted. Furthermore, counter to the initial hypothesis, river cities tend to change less than non-river cities after targeted disturbance of the systems. Finally, the results show that while there is a statistical morphological difference between river cities and non-river cities, this difference is not directly explained through the bridges.

    Conclusion: Integrating space syntax with statistical and geospatial analysis can throw light on the way in which the properties of city networks and urban structure reflect the relative effect of rivers on the morphology of river cities. The paper, finally, contributes through offering one piece of a better perception of the structure of river-cities that can support strategies of river-cities interaction as well as enhance our knowledge on the constraints and limits to that interaction.

    Download full text (pdf)
    Abshirini & Koch - Rivers as integration devices in cities
  • 5.
    Achberger, Christine
    et al.
    Göteborgs universitet.
    Chen, Deliang
    Göteborgs universitet.
    Rayner, David
    Göteborgs universitet.
    Nyberg, Lars
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Centre for Climate and Safety.
    Persson, Gunn
    SMHI.
    Future rainfall and flooding in Sweden: an integrative project to support climate-adaptation actions2013Conference paper (Refereed)
  • 6. Acosta, R. P.
    et al.
    Burls, N. J.
    Pound, M. J.
    Bradshaw, C. D.
    de Boer, Agatha M.
    Stockholm University, Faculty of Science, Department of Geological Sciences. Stockholm University, Faculty of Science, The Bolin Centre for Climate Research (together with KTH & SMHI).
    Herold, N.
    Huber, M.
    Liu, X.
    Donnadieu, Y.
    Farnsworth, A.
    Frigola, A.
    Lunt, D. J.
    von der Heydt, A. S.
    Hutchinson, D. K.
    Knorr, G.
    Lohmann, G.
    Marzocchi, A.
    Prange, M.
    Sarr, A. C.
    Li, X.
    Zhang, Z.
    A Model-Data Comparison of the Hydrological Response to Miocene Warmth: Leveraging the MioMIP1 Opportunistic Multi-Model Ensemble2024In: Paleoceanography and Paleoclimatology, ISSN 2572-4517, E-ISSN 2572-4525, Vol. 39, no 1, article id e2023PA004726Article in journal (Refereed)
    Abstract [en]

    The Miocene (23.03-5.33 Ma) is recognized as a period with close to modern-day paleogeography, yet a much warmer climate. With large uncertainties in future hydroclimate projections, Miocene conditions illustrate a potential future analog for the Earth system. A recent opportunistic Miocene Model Intercomparison Project 1 (MioMIP1) focused on synthesizing published Miocene climate simulations and comparing them with available temperature reconstructions. Here, we build on this effort by analyzing the hydrological cycle response to Miocene forcings across early-to-middle (E2MMIO; 20.03-11.6 Ma) and middle-to-late Miocene (M2LMIO; 11.5-5.33 Ma) simulations with CO2 concentrations ranging from 200 to 850 ppm and providing a model-data comparison against available precipitation reconstructions. We find global precipitation increases by similar to 2.1 and 2.3% per degree of warming for E2MMIO and M2LMIO simulations, respectively. Models generally agree on a wetter than modern-day tropics; mid and high-latitude, however, do not agree on the sign of subtropical precipitation changes with warming. Global monsoon analysis suggests most monsoon regions, except the North American Monsoon, experience higher precipitation rates under warmer conditions. Model-data comparison shows that mean annual precipitation is underestimated by the models regardless of CO2 concentration, particularly in the mid- to high-latitudes. This suggests that the models may not be (a) resolving key processes driving the hydrological cycle response to Miocene boundary conditions and/or (b) other boundary conditions or processes not considered here are critical to reproducing Miocene hydroclimate. This study highlights the challenges in modeling and reconstructing the Miocene hydrological cycle and serves as a baseline for future coordinated MioMIP efforts. This study looks at Earth's hydrological cycle during the Miocene (23-5 million years ago). During this period, the Earth's climate was 3-7 degrees C warmer than today, with carbon dioxide (CO2) estimates ranging between 400 and 850 ppm. Understanding how the hydrological cycle responded during warmer climate conditions can give us insight into what might happen as the Earth gets warmer. We analyzed a suite of Miocene paleoclimate simulations with different CO2 concentrations in the atmosphere and compared them against fossil plant data, which gives an estimate of the average annual rainfall during the period. We found that during the Miocene global rainfall increased by about 2.1%-2.3% for each degree of warming. The models agree that the tropics, mid- and high-latitude, became wetter than they are today but have lower agreement on whether subtropical areas got wetter or drier as they warmed. Compared to proxies, models consistently underestimated how much rain fell in a year, especially in the mid- to high-latitude. This illustrates the challenges in reconstructing the Miocene's hydrological cycle and suggests that the models might not fully capture the range of uncertainties associated with changes in the hydrological cycle due to warming or other factors that differentiated the Miocene. A multi-model comparison of the hydrological cycle in early-to-middle and middle-to-late Miocene simulations is conductedModels generally agree on wetter than modern tropics, middle and high latitudes, but not on the sign of subtropical precipitation changesModel-data comparison shows mean annual precipitation is underestimated by the models, particularly in the mid- to high-latitudes

  • 7. Adinugroho, Sigit
    et al.
    Vallot, Dorothée
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Westrin, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Strand, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Visual Information and Interaction. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction.
    Calving events detection and quantification from time-lapse images in Tunabreen glacier2015In: Proc. 9th International Conference on Information & Communication Technology and Systems, Piscataway, NJ: IEEE , 2015, p. 61-65Conference paper (Refereed)
  • 8.
    Adler, Peter
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Studier av geomorfologi på Mani, Peloponnesos, Grekland2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Mani peninsula in the south of Peloponnesos, Greece, is situated only 50 km from the subduction zone of the Hellenic arc. The active, tectonic processes taking place influence the geomorphology of the area. Through the use of remote sensing, analysis of a Digital Terrain Model and a five-day fieldwork study, certain areas of the southern peninsula’s geomorphology were examined for this project including recent processes that create landforms to date. Among those, chemical weathering and tectonics dominate. Also relict landforms were studied to get a greater understanding of the area. Fieldwork resulted in the discovery of two fields of rocks in one of the capes, which most likely were created before the cape underwent uplift to its current level. Also, a conglomerate superimposition of limestone in one of the bays showed indication that great mass movements took place when the surface was lower than today. A pediment is located on the west side of the Sagia Mountain. The asymmetry is probably due to a combination of tectonics and sea level changes.

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  • 9.
    Adrian, Lindqvist
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Koppling av grundvattenmodell och jordmodell med en geoteknisk sättningsmodell2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    From a construction engineering point of view groundwater drawdown in a confined aquifer can result in ground subsidence that can damage buildings and constructions. The connection between hydrogeology and soil mechanics is clear, however when estimating ground settlement as a result of groundwater drawdown the estimations are often rough. This is due to that settlement is traditionally calculated with methods that only allow calculations in single points where geotechnical data is estimated. Areas between these points are often left out of the calculations. Groundwater drawdown is seldom simulated with acknowledged software programs like Modflow when estimating groundwater lowering and the affected area.This study combines a groundwater model simulated in Modflow and a soil strata model, interpolated with Kriging, with settlement calculations. This ends up as a an integrated soil settlement model which has the purpose to generate overview maps over areas that are sensitive to settlement as a result of ground water lowering. The integrated model is programmed in Octave for this study. The model is then tested with a case study that uses data from a real construction project in the area of Mälardalen. A hypothetical case of ground water lowering is simulated for the case study. Fundamental hydro-geological theory is used to estimate loads and effective stresses from the lowering of the water table.The result from the integrated model has been validated against calculations of settlement in the software Geosuite Settlement which is an acknowledged method for settlement calculations. This shows that the integrated model calculates settlement with great precision. The modeled initial ground water table is compared with a kriginginterpolated groundwater table which is based on data from ground water pipes in the area. Based on the comparison the initial ground water conditions simulated in Modflow are accepted. This simulated ground water model has the soil model and also a water balance integrated.The results from the case study show that unexpectedly large ground settlements can occur even far from the source of the ground water lowering.For the case study three different soil models are used, both in the ground water model and in the integrated model. The soil models differ in a way that they are based on different amounts of data from which the kriging interpolation is done. The purpose for this is to investigate what effects this might have on the ground water model and the integrated model respectively. The results from these different simulations show insignificantly small differences.

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  • 10.
    Afrifa, Yamoah Kweku Kyei
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Reconstruction of the Southeast Asian hydro-climate using biomarkers and their hydrogen isotopic composition2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Southeast Asia is characterized by a monsoonal climate, with distinct wet and dry seasons. This has great impact on societies, agriculture and infrastructures. Despite the critical importance to understand the mechanisms that influence the variability of the Asian Monsoon, there is scarcity of both historical and paleoclimate proxy data from Southeast Asia. For this reason, two lakes from Thailand, Lake Pa Kho (LPK) and Lake Nong Thale Pron (NTP), which are located in the northeastern and southern part of Thailand, respectively, were cored. The region also offers the opportunity to study the potential influence of climate on the Angkor civilization. Overall, this project seeks to improve our understanding of the mechanisms that contribute to Asian monsoon variability and how the variability influenced Angkor Civilization. Here I present results on a 2000-years sediment record from LPK. The most important part of the work presented here consists of compound-specific hydrogen isotope ratios (δD), which are used to infer past changes in the hydrological cycle of Southeast Asia. This approach is based on the premise that δD of lipid biomarkers from plants, algae and microorganisms deposited in sediments reflects the δD of their source water, which in turn is influenced by local hydrology. A rapid increase in precipitation is inferred from ca. 700 to ca. 850 AD, after a long dry phase. The inferred shift to wet conditions likely contributed to the rise of the Angkor Civilization, by boosting agriculture. However, gradual drying occurred at around 900 AD until the 19th century. This long-term decline in precipitation, favoring ever more frequent occurrences of severe droughts, likely also contributed to the demise and fall of the Angkor, around 1400 AD. Comparison with other hydroclimate proxy records revealed that wet conditions in tropical SE Asia corresponded to a dry Western Pacific, wet conditions in the East Pacific, and vice versa - a pattern that can be explained by opposing centers of convection and subsidence. Moreover, our tropical record also appears to be anti-correlated with the subtropical East Asian Monsoon, possibly caused by rainout effects along moisture trajectories. These long-term rainfall shifts closely match patterns observed during periods of strong El Niño, and suggests a central role for Pacific Walker circulation as a driver of centennial-scale hydroclimatic change. Besides these results from LPK oriented towards reconstructing hydroclimate, I also present some initial results concerning the evolution of the plant community of LPK, based on compound specific 13C analysis, as well as first biomarker results from NTP.

  • 11. Agangi, Andrea
    et al.
    Reddy, S M
    Plavsa, D
    Vieru, C
    Selvaraja, V
    LaFlamme, C
    Jeon, Heejin
    Swedish Museum of Natural History, Department of Geology.
    Martin, L
    Nozaki, T
    Takaya, Y
    Suzuki, K
    Subsurface deposition of Cu-rich massive sulphide underneath a Palaeoproterozoic seafloor hydrothermal system—the Red Bore prospect, Western Australia2018In: Mineralium Deposita, p. 1-18Article in journal (Refereed)
  • 12.
    Agard, Shenelle
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    In-Situ Gold Resource Estimation Using Satellite Remote Sensing and Machine Learning in Defunct Tailing Storage Facilities (South Africa)2023Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    The mining industry generates billions of tonnes of waste annually, which is often stored in tailings storage facilities (TSF). This waste is generated from the extraction of ore from surface or underground mines, as well as from metallurgical processing and low-grade stockpiles. TSF can have significant environmental impacts, as they can cause acid mine drainage resulting in the leaching and transport of heavy metals into ground and surface waters. With increasing demand for critical raw material, recent studies have shown that the valorisation of mine waste can be a potential secondary source of critical raw materials. The valorisation of mine waste is possible when the waste is accurately characterised.A novel method that uses multispectral satellite remote sensing and machine learning to estimate the mineral resource in a defunct TSF in the Witwatersrand Basin, South Africa is proposed in this research. Four machine learning models: 1) random forest (RF); 2) adaptive boosting (AB); 3) extra trees (ET); and 4) k-nearest neighbours are developed using supervised machine learning. The models are trained using training data acquired from a TSF with known gold concentration located 3 kilometres from the TSF and deployed on the TSF to predict the gold grades. The results of the machine learning model predictions indicates that machine learning models had high performances for predicting gold grades in the TSF. The AB, RF and ET, models performed best. Their performances were evaluated using the coefficient of determination (R2) value. The R2 values for the machine learning models were 0.95, 0.92, 0.87 and 0.70 for AB, ET, RF and kNN respectively. The mean gold grade predicted was 0.44 g/t by all machine learning models. This was compared to a 2D surficial geostatistical model which estimated 0.35g/t gold in the TSF using ordinary kriging and a 2D vertically averaged geostatistical model with an estimated 0.4 g/t mean gold grade. The short-wave infrared (SWIR) - band 11 at a 20 m spatial resolution had the highest correlation with the reflectance of gold in the TSF. This study demonstrated the value of leveraging multi-spectral remote sensing data and machine learning to perform mineral resource estimation in defunct TSF.

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  • 13.
    Ahrens, Lutz
    et al.
    Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Box 7050, SE-75007 Uppsala, Sweden..
    Gashaw, Habiba
    Univ Addis Ababa, Ethiopian Inst Water Resources, Addis Ababa, Ethiopia..
    Sjöholm, Margareta
    Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Box 7050, SE-75007 Uppsala, Sweden..
    Gebrehiwot, Solomon Gebreyohannis
    Univ Addis Ababa, Ethiopian Inst Water Resources, Addis Ababa, Ethiopia..
    Getahun, Abebe
    Univ Addis Ababa, Dept Zool Sci, Addis Ababa, Ethiopia.;Hawassa Univ, Dept Biol, POB 5, Hawassa, Ethiopia..
    Derbe, Ermias
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Hawassa Univ, Dept Biol, POB 5, Hawassa, Ethiopia..
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Box 7050, SE-75007 Uppsala, Sweden..
    Åkerblom, Staffan
    Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Box 7050, SE-75007 Uppsala, Sweden..
    Poly- and perfluoroalkylated substances (PFASs) in water, sediment and fish muscle tissue from Lake Tana, Ethiopia and implications for human exposure2016In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 165, p. 352-357Article in journal (Refereed)
    Abstract [en]

    Lake Tana is Ethiopia's largest lake and there are plans to increase the harvest of fish from the lake. The objective of this study was to assess the levels of poly- and perfluoroalkyl substances (PFASs) in different compartments of the lake (water, sediment, and fish muscle tissue), and its implications for human exposure. The results showed higher PFAS concentrations in piscivorous fish species (Labeobarbus mega-stoma and Labeobarbus gorguari) than non-piscivorous species (Labeobarbus intermedius, Oreochromis niloticus and Clarias gariepinus) and also spatial distribution similarities. The Sigma PFAS concentrations ranged from 0.073 to 5.6 ng L-1 (on average, 2.9 ng L-1) in surface water, 0.22-0.55 ng g(-1) dry weight (dw) (on average, 0.30 ng g(-1) dw) in surface sediment, and non-detected to 5.8 ng g(-1) wet weight (ww) (on average, 1.2 ng g(-1) ww) in all fish species. The relative risk (RR) indicates that the consumption of fish contaminated with perfiuorooctane sulfonate (PFOS) will likely not cause any harmful effects for the Ethiopian fish eating population. However, mixture toxicity of the sum of PFASs, individual fish consumption patterns and increasing fish consumption are important factors to consider in future risk assessments.

  • 14. Albani, S
    et al.
    Mahowald, N M
    Winckler, G
    Anderson, R F
    Bradtmiller, L I
    Delmonte, B
    François, R
    Goman, M
    Heavens, N G
    Hesse, P P
    Hovan, S A
    Kang, S G
    Kohfeld, K E
    Lu, H
    Maggi, V
    Mason, A
    Mayewski, P A
    McGee, D
    Miao, X
    Otto-Bliesner, L
    Perry, A T
    Pourmand, A
    Roberts, H M
    Rosenbloom, N
    Stevens, Thomas
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Sun, J
    Twelve thousand years of dust: the Holocene global dust cycle constrained by natural archives2015In: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 11, no 6, p. 869-903Article in journal (Refereed)
    Abstract [en]

    Mineral dust plays an important role in the climate system by interacting with radiation, clouds, and biogeochemical cycles. In addition, natural archives show that the dust cycle experienced variability in the past in response to global and local climate change. The compilation of the DIRTMAP paleodust datasets in the last two decades provided a target for paleoclimate models that include the dust cycle, following a time slice approach. We propose an innovative framework to organize a paleodust dataset that moves on from the positive experience of DIRTMAP and takes into account new scientific challenges, by providing a concise and accessible dataset of temporally resolved records of dust mass accumulation rates and particle grain-size distributions. We consider data from ice cores, marine sediments, loess/paleosol sequences, lake sediments, and peat bogs for this compilation, with a temporal focus on the Holocene period. This global compilation allows investigation of the potential, uncertainties and confidence level of dust mass accumulation rates reconstructions, and highlights the importance of dust particle size information for accurate and quantitative reconstructions of the dust cycle. After applying criteria that help to establish that the data considered represent changes in dust deposition, 43 paleodust records have been identified, with the highest density of dust deposition data occurring in the North Atlantic region. Although the temporal evolution of dust in the North Atlantic appears consistent across several cores and suggest that minimum dust fluxes are likely observed during the Early to mid-Holocene period (6000–8000 years ago), the magnitude of dust fluxes in these observations is not fully consistent, suggesting that more work needs to be done to synthesize datasets for the Holocene. Based on the data compilation, we used the Community Earth System Model to estimate the mass balance and variability of the global dust cycle during the Holocene, with dust load ranging from 17.1 to 20.5 Tg between 2000 and 10 000 years ago, and a minimum in the Early to Mid-Holocene (6000–8000 years ago).

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    paper
  • 15.
    Ali, Fadi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Urban classification by pixel and object-based approaches for very high resolution imagery2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Recently, there is a tremendous amount of high resolution imagery that wasn’t available years ago, mainly because of the advancement of the technology in capturing such images. Most of the very high resolution (VHR) imagery comes in three bands only the red, green and blue (RGB), whereas, the importance of using such imagery in remote sensing studies has been only considered lately, despite that, there are no enough studies examining the usefulness of these imagery in urban applications. This research proposes a method to investigate high resolution imagery to analyse an urban area using UAV imagery for land use and land cover classification. Remote sensing imagery comes in various characteristics and format from different sources, most commonly from satellite and airborne platforms. Recently, unmanned aerial vehicles (UAVs) have become a very good potential source to collect geographic data with new unique properties, most important asset is the VHR of spatiotemporal data structure. UAV systems are as a promising technology that will advance not only remote sensing but GIScience as well. UAVs imagery has been gaining popularity in the last decade for various remote sensing and GIS applications in general, and particularly in image analysis and classification. One of the concerns of UAV imagery is finding an optimal approach to classify UAV imagery which is usually hard to define, because many variables are involved in the process such as the properties of the image source and purpose of the classification. The main objective of this research is evaluating land use / land cover (LULC) classification for urban areas, whereas the data of the study area consists of VHR imagery of RGB bands collected by a basic, off-shelf and simple UAV. LULC classification was conducted by pixel and object-based approaches, where supervised algorithms were used for both approaches to classify the image. In pixel-based image analysis, three different algorithms were used to create a final classified map, where one algorithm was used in the object-based image analysis. The study also tested the effectiveness of object-based approach instead of pixel-based in order to minimize the difficulty in classifying mixed pixels in VHR imagery, while identifying all possible classes in the scene and maintain the high accuracy. Both approaches were applied to a UAV image with three spectral bands (red, green and blue), in addition to a DEM layer that was added later to the image as ancillary data. Previous studies of comparing pixel-based and object-based classification approaches claims that object-based had produced better results of classes for VHR imagery. Meanwhile several trade-offs are being made when selecting a classification approach that varies from different perspectives and factors such as time cost, trial and error, and subjectivity.

          Classification based on pixels was approached in this study through supervised learning algorithms, where the classification process included all necessary steps such as selecting representative training samples and creating a spectral signature file. The process in object-based classification included segmenting the UAV’s imagery and creating class rules by using feature extraction. In addition, the incorporation of hue, saturation and intensity (IHS) colour domain and Principle Component Analysis (PCA) layers were tested to evaluate the ability of such method to produce better results of classes for simple UAVs imagery. These UAVs are usually equipped with only RGB colour sensors, where combining more derived colour bands such as IHS has been proven useful in prior studies for object-based image analysis (OBIA) of UAV’s imagery, however, incorporating the IHS domain and PCA layers in this research did not provide much better classes. For the pixel-based classification approach, it was found that Maximum Likelihood algorithm performs better for VHR of UAV imagery than the other two algorithms, the Minimum Distance and Mahalanobis Distance. The difference in the overall accuracy for all algorithms in the pixel-based approach was obvious, where the values for Maximum Likelihood, Minimum Distance and Mahalanobis Distance were respectively as 86%, 80% and 76%. The Average Precision (AP) measure was calculated to compare between the pixel and object-based approaches, the result was higher in the object-based approach when applied for the buildings class, the AP measure for object-based classification was 0.9621 and 0.9152 for pixel-based classification. The results revealed that pixel-based classification is still effective and can be applicable for UAV imagery, however, the object-based classification that was done by the Nearest Neighbour algorithm has produced more appealing classes with higher accuracy. Also, it was concluded that OBIA has more power for extracting geographic information and easier integration within the GIS, whereas the result of this research is estimated to be applicable for classifying UAV’s imagery used for LULC applications.

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  • 16. Ali, Kamal A
    et al.
    Jeon, Heejin
    Swedish Museum of Natural History, Department of Geology.
    Andresen, Arild
    Li, Shuang-Qing
    Harbi, Hesham M
    Hegner, Ernst
    U–Pb zircon geochronology and Nd–Hf–O isotopic systematics of the Neoproterozoic Hadb adh Dayheen ring complex, Central Arabian Shield, Saudi Arabia2014In: Lithos, Vol. 206, p. 348-360Article in journal (Refereed)
  • 17. Allah Tavakoli, Yahya
    et al.
    Amin, Hadi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Bagheri, Hamidreza
    Bagherbandi, Mohammad
    On an approach to surface mass change detection from satellite gravimetry, a case study of barystatic sea-level, ice-sheet mass and basin mass changes2022In: Article in journal (Refereed)
  • 18.
    Al-Soud, Madhat Shakir
    et al.
    College of Engineering, Mustansiriyah University, Baghdad, Iraq.
    Fartosy, Sabah Hassan
    College of Engineering, Mustansiriyah University, Baghdad, Iraq.
    Jabur, Aqeel Raheem
    College of Engineering, Mustansiriyah University, Baghdad, Iraq.
    Majeed, Muhannd Waleed
    College of Engineering, Mustansiriyah University, Baghdad, Iraq.
    Madhloom, Huda M.
    College of Engineering, Mustansiriyah University, Baghdad, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Sustainable Improvement Of Bentonite Clay Characteristics By Adding Pulverized Waste Glass2022In: International Journal of GEOMATE, ISSN 2186-2982, Vol. 23, no 95, p. 10-19Article in journal (Refereed)
    Abstract [en]

    Bentonite clay is the soil that undergoes high volume changes (swelling) when its moisture content increases. The soil swelling may cause structural damage leading to damage to structural members like cracking in reinforced foundations and borders, curbs swelling, and eventually produces deformation indoors and on floors. In this study, Bentonite clay with expansive characteristics was used and mixed with various amounts of Pulverized waste glass PWG (0%, 5%, 10%, and 15%). Two types of PWG were prepared: fine glass (passing sieve No. 200) and coarse glass (passing sieve No. 2 mm). Laboratory experiments were performed on Bentonite specimens blended with different amounts of PWG. The results showed that the addition of 15% by Bentonite weight of 2 mm of PWG reduces the Atterberg limits considerably. Moreover, a noticeable reduction was observed in the Bentonite samples’ free swell and swelling pressure after being treated with different amounts of PWG. The observed advantages of adding the PWG to Bentonite clay soil by decreasing the volume changes and enhancing the overall properties of Bentonite clay reflect the suitability of using PGW as a good soil stabilizer. Besides reducing the impact of waste glass on the environment due to its non-biodegradable nature.

  • 19. Alvarez, Belinda
    et al.
    Frings, Patrick J
    Swedish Museum of Natural History, Department of Geology.
    Clymans, Wim
    Fontorbe, Guillaume
    Conley, Daniel
    Assessing the Potential of Sponges (Porifera) as Indicators of Ocean Dissolved Si Concentrations2017In: Frontiers in Marine Science, E-ISSN 2296-7745, Vol. 4, no 373Article in journal (Refereed)
    Abstract [en]

    We explore the distribution of sponges along dissolved silica (dSi) concentration gradients to test whether sponge assemblages are related to dSi and to assess the validity of fossil sponges as a palaeoecological tool for inferring dSi concentrations of the past oceans. We extracted sponge records from the publically available Global Biodiversity Information Facility (GBIF) database and linked these records with ocean physiochemical data to evaluate if there is any correspondence between dSi concentrations of the waters sponges inhabit and their distribution. Over 320,000 records of Porifera were available, of which 62,360 met strict quality control criteria. Our analyses was limited to the taxonomic levels of family, order and class. Because dSi concentration is correlated with depth in the modern ocean, we also explored sponge taxa distributions as a function of depth. We observe that while some sponge taxa appear to have dSi preferences (e.g., class Hexactinellida occurs mostly at high dSi), the overall distribution of sponge orders and families along dSi gradients is not sufficiently differentiated to unambiguously relate dSi concentrations to sponge taxa assemblages. We also observe that sponge taxa tend to be similarly distributed along a depth gradient. In other words, both dSi and/or another variable that depth is a surrogate for, may play a role in controlling sponge spatial distribution and the challenge is to distinguish between the two. We conclude that inferences about palaeo-dSi concentrations drawn from the abundance of sponges in the stratigraphic records must be treated cautiously as these animals are adapted to a great range of dSi conditions and likely other underlying variables that are related to depth. Our analysis provides a quantification of the dSi ranges of common sponge taxa, expands on previous knowledge related to their bathymetry preferences and suggest that sponge taxa assemblages are not related to particular dSi conditions. 

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  • 20.
    Amin, Hadi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Study on the Earth’s Surface Mass Variations using Satellite Gravimetry Observations2022Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Our complex planet is continuously undergoing temporal and spatial changes. In this context, ongoing processes in the Earth subsystems (geosphere, biosphere, cryosphere, hydrosphere, and atmosphere) cause changes in the gravity field of the Earth across a wide range of temporal and spatial scales. Accordingly, by both spatially and temporally tracing our planet’s ever-changing gravity field, scientists can better constrain the underlying processes contributing to such dynamic changes of mass distribution within the Earth system. Monitoring the Earth’s gravity field and its temporal variations is essential, among others, for tracking disasters and specifying land areas with a high risk of flooding, earthquakes, and droughts, movements of tectonic plates, and providing accurate positioning through satellite positioning technology. On short-term timescales, temporal variations in the Earth’s gravity field are mainly caused by the movement of water in its various forms. Accordingly, sea-level variations and ice-sheet and glacier changes, which are known as critical indicators of global warming and climate change, can be accurately monitored by tracking the Earth’s gravity field changes. Since there is a close link between water redistribution and the Earth’s energy cycle, climate system, food security, human and ecosystem health, energy generation, economic and societal development, and climate extremes (droughts and floods), it is essential to accurately monitor water mass exchange between the Earth system components. Among all observational techniques, satellite gravimetry has provided an integrated global view of ongoing processes within the Earth system. The current generation of satellite gravimetry missions (the Gravity Recovery and Climate Experiment (GRACE) mission and its successor, GRACE Follow-On) has dramatically revolutionized our understanding of dynamic processes in the Earth’s surface and, consequently, has significantly improved our understanding of the Earth’s climate system. By considering different aspects of studying the Earth’s gravity field, this thesis brings new insights to the determination and analysis of the mass change in the Earth system. First, by studying the shortcomings of the common techniques of estimating the geoid potential, a new approach is examined that simultaneously estimates the geoid potential, W0, and the geometrical parameters of the reference Mean Earth Ellipsoid (MEE). In this regard, as the geoid needs to be considered as a static equipotential surface, the sensitivity of the estimations to the time dependent Earth’s gravity field changes is studied. Secondly, relying on the GRACE monthly gravity fields and the complementary observational techniques, and by pushing the limit of GRACE, mass redistribution over land and ocean is investigated. Within the ocean, satellite altimetry and Argo products are utilized along with the GRACE monthly solutions for quantifying the global barystatic sea-level change and assessing the closure of the global mean sea level budget. Over land, a region with relatively high temporal mass change (oil and water extraction) is chosen in which by taking advantage of having in-situ observations and hydrological models, the ability of GRACE products in quantifying the changes in groundwater storage is studied. In this frame, for both the ocean and land studies, different aspects of the processing of GRACE monthly gravity fields are investigated and GRACE inherent errors are addressed appropriately to arrive at reliable and accurate estimates of the Earth’s surface mass change. As the final contribution in this thesis, a rigorous analytical model for detecting surface mass change from the time-variable gravity solutions is proposed and examined in different case studies of surface mass change. Since the launch of the GRACE twin satellites, the GRACE(-FO) time-varying gravity fields are conventionally converted into the surface mass change using a spherical analytical model that approximates the Earth by a sphere. More recently, the analytical mass change detection model has been improved by considering an ellipsoid as the shape of the Earth, which improved the previous estimations of surface mass change, especially over high latitudes with relatively large mass change signals. However, by taking into account the real shape of the Earth and considering more realistic assumptions, a new analytical solution for the problem of surface mass change detection from the time-varying gravity fields is proposed in this thesis. It is shown that the simplistic spherical and ellipsoidal geometries are no longer tenable and the new model surpasses the common spherical approach and its ellipsoidal version.

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  • 21.
    Anderson, Kevin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Uppsala Centre for Sustainable Development, CSD Uppsala. Univ Manchester, Tyndall Ctr, Manchester M13 9PL, Lancs, England..
    Peters, Glen
    CICERO, Pb 1129 Blindern, N-0318 Oslo, Norway..
    The trouble with negative emissions2016In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 354, no 6309, p. 182-183Article in journal (Other academic)
  • 22. Anderson, N. John
    et al.
    Saros, Jasmine E.
    Bullard, Joanna E.
    Cahoon, Sean M. P.
    Mcgowan, Suzanne
    Bagshaw, Elizabeth A.
    Barry, Christopher D.
    Bindler, Richard
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Burpee, Benjamin T.
    Carrivick, Jonathan L.
    Fowler, Rachel A.
    Fox, Anthony D.
    Fritz, Sherilyn C.
    Giles, Madeleine E.
    Hamerlik, Ladislav
    Ingeman-Nielsen, Thomas
    Law, Antonia C.
    Mernild, Sebastian H.
    Northington, Robert M.
    Osburn, Christopher L.
    Pla-Rabes, Sergi
    Post, Eric
    Telling, Jon
    Stroud, David A.
    Whiteford, Erika J.
    Yallop, Marian L.
    Yde, Jacob C.
    The Arctic in the Twenty-First Century: Changing Biogeochemical Linkages across a Paraglacial Landscape of Greenland2017In: BioScience, ISSN 0006-3568, E-ISSN 1525-3244, Vol. 67, no 2, p. 118-133Article in journal (Refereed)
    Abstract [en]

    The Kangerlussuaq area of southwest Greenland encompasses diverse ecological, geomorphic, and climate gradients that function over a range of spatial and temporal scales. Ecosystems range from the microbial communities on the ice sheet and moisture-stressed terrestrial vegetation (and their associated herbivores) to freshwater and oligosaline lakes. These ecosystems are linked by a dynamic glacio-fluvial-aeolian geomorphic system that transports water, geological material, organic carbon and nutrients from the glacier surface to adjacent terrestrial and aquatic systems. This paraglacial system is now subject to substantial change because of rapid regional warming since 2000. Here, we describe changes in the eco-and geomorphic systems at a range of timescales and explore rapid future change in the links that integrate these systems. We highlight the importance of cross-system subsidies at the landscape scale and, importantly, how these might change in the near future as the Arctic is expected to continue to warm.

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  • 23. Anderson, N.J.
    et al.
    Appleby, P.G.
    Bindler, Richard
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Renberg, I.
    Conley, D.J.
    Fritz, S.C.
    Jones, V.J.
    Whiteford, E.J.
    Yang, H
    Landscape-Scale Variability of Organic Carbon Burial by SW Greenland Lakes2019In: Ecosystems (New York. Print), ISSN 1432-9840, E-ISSN 1435-0629, Vol. 22, no 8, p. 1706-1720Article in journal (Refereed)
    Abstract [en]

    Lakes are a key feature of arctic landscapes and can be an important component of regional organic carbon (OC) budgets, but C burial rates are not well estimated. 210Pb-dated sediment cores and carbon and organic matter (as loss-on-ignition) content were used to estimate OC burial for 16 lakes in SW Greenland. Burial rates were corrected for sediment focusing using the 210Pb flux method. The study lakes span a range of water chemistries (conductivity range 25–3400 µS cm−1), areas (< 4–100 ha) and maximum depths (~ 10–50 m). The regional average focusing-corrected OC accumulation rate was ~ 2 g C m−2 y−1 prior to ~ 1950 and 3.6 g C m−2 y−1 after 1950. Among-lake variability in post-1950 OC AR was correlated with in-lake dissolved organic carbon concentration, conductivity, altitude and location along the fjord. Twelve lakes showed an increase in mean OC AR over the analyzed time period, ~ 1880–2000; as the study area was cooling until recently, this increase is probably attributable to other global change processes, for example, altered inputs of N or P. There are ~ 20,000 lakes in the study area ranging from ~ 1 ha to more than 130 km2, although over 83% of lakes are less than 10 ha. Extrapolating the mean post-1950 OC AR (3.6 g C m−2 y−1) to all lakes larger than 1000 ha and applying a lower rate of ~ 2 g C m−2 y−1 to large lakes (> 1000 ha) suggests a regional annual lake OC burial rate of ~ 10.14 × 109 g C y−1 post 1950. Given the low C content of soils in this area, lakes represent a substantial regional C store.

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  • 24.
    Andersson, Andreas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Department of Ecotechnology and Sustainable Building Engineering, Mid Sweden University, Östersund, Sweden.
    Falck, Eva
    Sjöblom, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Department of Arctic Geophysics, University Centre in Svalbard, Longyearbyen, Norway.
    Kljun, Natascha
    Sahlée, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Omar, Abdirahaman
    Rutgersson, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Air-sea gas transfer in high Arctic fjords2017In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 44, no 5, p. 2519-2526Article in journal (Refereed)
    Abstract [en]

    In Arctic fjords and high-latitude seas, strong surface cooling dominates during a large part of the year, generating water-side convection (w*w) and enhanced turbulence in the water. These regions are key areas for the global carbon cycle; thus, a correct description of their air-sea gas exchange is crucial. CO2-data were measured via the eddy covariance technique in marine Arctic conditions and reveal that water-side convection has a major impact on the gas transfer velocity. This is observed even at wind speeds as high as 9 m s-1, where convective motions are generally thought to be suppressed by wind-driven turbulence. The enhanced air-sea transfer of CO2 caused by water-side convection nearly doubled the CO2uptake, after scaled to open sea conditions the contribution from  to the CO2 flux remained as high as 34%; this phenomenon is expected to be highly important for the total carbon uptake in marine Arctic areas.

  • 25.
    Andersson Cada, Emil
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Grundvattenpotential i Västerviks kommun: Geostatistiska metoder i en GIS-miljö2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this study, groundwater resource potential (GRP) for Västervik municipality has been investigated using the methodology developed in the article by Earon et al. (2015). The aim was to test the reliability of the methodology for groundwater mapping, as to further add to the knowledge base of groundwater access. The GRP-methodology is a linear additive multicriteria analysis where geohydrological indicators are scored, classified into groups, then multiplied by weights calculated using Principal Component Analysis (PCA). The classification and validation were performed against specific capacity [L/(h*m)], which is a well's capacity calculated at drilling, per meter well. GRP was calculated in different sets based on 13 geohydrological variables such as altitude and Topographic Wetness Index (TWI). The results included correlation tests for Kendall's tau (0.06-0.13), Spearmans rho (0.09-0.19) with a total accuracy of 52-55%. Positive but low values ​​for Cohen´s kappa indicated that all calculations performed better than a random generator, but not by margin. Calculations of VIP (Variables importance on PLS projection), based on Partial Least Squares (PLS), identified Altitude, Earth type, Drainage density and TWI as the most influential indicators for the analysis.The conclusions of this study were, among other things, that the GRP methodology had low predictivity due to the weak relationships between the indicators and the specific capacity. The weaknesses could also be due to the fact that specific capacity has weaknesses as a validation variable for groundwater resource potential linked to uncertainties of the capacity measured at wellbore. The study shows that further development of the weighting scheme by integrating PLS would be beneficial, as PLS calculates the variance of the indicators based on the specific capacity, instead of assuming it as a PCA. 

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  • 26.
    Andersson, Colin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Hoset, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Kusterosion på sydvästra Gotland: En undersökning i GIS och berggrundsgeologi2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Southwestern Gotland has a relatively diverse bedrock where both sandstone, limestone and marl areexposed. The purpose of the survey has been to investigate differences in coastal erosion regarding thecontent of the bedrock. This was done by taking samples from 9 different locations which were laterexamined in point load tests and a slake durability test. A GIS-analysis was also done where the coastalarea in old aerial images and modern orthophotos were compared. The results showed that the sandstoneand marl samples were approximately equally prone to break and that limestone was less prone. Theslake durability test showed that sandstone from one site had the least resistance to abrasion, sandstonefrom the marl areas had greater resistance and that the limestone area had marginally greater resistancethan the marl areas. The GIS analysis indicated that the sandstone and marl areas had a relatively highsensitivity to coastal erosion and that the limestone area was not particularly exposed to coastal erosion.

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  • 27.
    Andersson, Jan-Olov
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Centre for Climate and Safety.
    Blumenthal, Barbara
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Centre for Climate and Safety.
    Nyberg, Lars
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Centre for Climate and Safety.
    Kartering av översvämningsrisker vid Vänern2013Report (Other academic)
    Abstract [sv]

    I denna studie genomfördes en översvämningskartering och -analys som utgick från fyra

    extrema vattennivåer i Vänern. Baserat på höjddata från den Nya Nationella Höjdmodellen

    (NNH) generades utbredningspolygoner med hjälp av GIS för de fyra översvämningsnivåerna.

    Överlagringsanalyser gjordes sedan med kartskikt för väg, mark och byggnader

    samt för vissa kommuner även befolkning för att urskilja vägsträckor, markområden,

    byggnader och boende inom översvämningsutbredningen vid de fyra nivåerna.

    Översvämningskartor togs fram i pdf-format och Google Earth-format. GIS-analysen har

    genererat kvantitativa data för översvämmade vägsträckor, markytor antal byggnader etc.

    Vidare har en objektsbaserad analys genomförts utifrån kartmaterial och kommunala data

    över sårbara anläggningar och funktioner. Resultaten har sammanställts kommunvis och

    för Vänerområdet i sin helhet i form av text, tabeller och diagram.

    Det som drabbas först vid en översvämning i Vänern är dels objekt som utifrån sina

    funktioner ligger vattennära t.ex. fritidsanläggningar, men även viktiga vägar som E18 och

    E45. Järnvägsträckan Göteborg-Karlstad-Stockholm översvämmas redan vid 100-årsnivån.

    Med stigande vattennivå drabbas allt fler objekt och samhällsviktiga funktioner. De städer

    som påverkas mest är Karlstad, Kristinehamn, Mariestad, Lidköping och Vänersborg.

    De direkta skadekostnaderna för en 100-årsnivå i Vänern har beräknats till 100-240 Mkr,

    där en möjlig vindeffekt kan ge ytterligare upp till 120 Mkr i skadekostnader. För en

    dimensionerande nivå skulle skadekostnaderna bli av en helt annan storleksordning och

    uppgå till ca 9,8 miljarder kr. Vid denna nivå skulle stora indirekta skador uppstå som vi

    inte har haft möjlighet att värdera ekonomiskt. De största kostnaderna kan kopplas till

    översvämmade byggnader.

    I en absolut jämförelse med Mälaren av kvantitativa data för översvämmade vägar,

    markområden och antal byggnader är konsekvenserna vid Vänern något lägre.

    Studien genomfördes på uppdrag av och i samarbete med

    Vänerkommunerna i samverkan om

    Vänerns reglering.

     

  • 28.
    Andersson-Sköld, Yvonne
    et al.
    Swedish Geotechnical Institute .
    Bergman, Ramona
    Swedish Geotechnical Institute .
    Nyberg, Lars
    Karlstad University, Faculty of Social and Life Sciences, Centre for Climate and Safety.
    Johansson, Magnus
    Karlstad University, Faculty of Social and Life Sciences, Department of Health and Environmental Sciences.
    Persson, Erik
    Karlstad University, Faculty of Social and Life Sciences, Department of Health and Environmental Sciences.
    Effekter av samhällets säkerhetsåtgärder (ESS) - en kartering av arbetet idag med fokus på översvämningar, ras och skred2012Report (Other academic)
  • 29.
    Andren, Elinor
    et al.
    Sodertom Univ, Sch Nat Sci Technol & Environm Studies, Huddinge, Sweden..
    Klimaschewski, Andrea
    Queens Univ Belfast, Sch Geog Archaeol & Palaeoecol, Belfast BT7 1NN, Antrim, North Ireland..
    Self, Angela E.
    Nat Hist Museum, Dept Life Sci, London SW7 5BD, England..
    Amour, Natalie St.
    Univ Western Ontario, Dept Earth Sci, London, ON, Canada..
    Andreev, Andrei A.
    Univ Cologne, Inst Geol & Mineral, D-50931 Cologne, Germany.;Kazan Fed Univ, Inst Geol & Petr Technol, Kazan, Russia..
    Bennett, Keith D.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology. Queens Univ Belfast, Sch Geog Archaeol & Palaeoecol, Belfast BT7 1NN, Antrim, North Ireland..
    Conley, Daniel J.
    Lund Univ, Dept Geol, Quaternary Sci, Lund, Sweden..
    Edwards, Thomas W. D.
    Univ Waterloo, Dept Earth & Environm Sci, Waterloo, ON N2L 3G1, Canada..
    Solovieva, Nadia
    Kazan Fed Univ, Inst Geol & Petr Technol, Kazan, Russia.;UCL, Dept Geog, London WC1E 6BT, England..
    Harnmarlund, Dan
    Lund Univ, Dept Geol, Quaternary Sci, Lund, Sweden..
    Holocene climate and environmental change in north-eastern Kamchatka (Russian Far East), inferred from a multi-proxy study of lake sediments2015In: Global and Planetary Change, ISSN 0921-8181, E-ISSN 1872-6364, Vol. 134, p. 41-54Article in journal (Refereed)
    Abstract [en]

    A sediment record from a small lake in the north-eastern part of the Kamchatka Peninsula has been investigated in a multi-proxy study to gain knowledge of Holocene climatic and environmental change. Pollen, diatoms, chironomids and selected geochemical parameters were analysed and the sediment record was dated with radiocarbon. The study shows Holocene changes in the terrestrial vegetation as well as responses of the lake ecosystern to catchment maturity and multiple stressors, such as climate change and volcanic eruptions. Climate change is the major driving force resulting in the recorded environmental changes in the lake, although recurrent tephra deposition events also contributed. The sediment record has an age at the base of about 10,000 cal yrs BP, and during the first 400 years the climate was cold and the lake exhibited extensive ice-cover during winter and relatively low primary production. Soils in the catchment were poor with shrub alder and birches dominating the vegetation surrounding the lake. At about 9600-8900 cal yrs BP the climate was cold and moist, and strong seasonal wind stress resulted in reduced ice-cover and increased primary production. After ca. 8900 cal yrs BP the forest density increased around the lake, runoff decreased in a generally drier climate resulting in decreased primary production in the lake until ca. 7000 cal yrs BP. This generally dry climate was interrupted by a brief climatic perturbation, possibly attributed to the 8.2 ka event, indicating increasingly windy conditions with thick snow cover, reduced ice-cover and slightly elevated primary production in the lake. The diatom record shows maximum thermal stratification at ca. 6300-5800 cal yrs BP and indicates together with the geochemical proxies a dry and slightly warmer climate resulting in a high productive lake. The most remarkably change in the catchment vegetation occurred at ca. 4200 cal yrs BP in the form of a conspicuous increase in Siberian dwarf pine (Pinus pumila), indicating a shift to a cooler climate with a thicker and more long-lasting snow cover. This vegetational change was accompanied by marked shifts in the diatom and chironomid stratigraphies, which are also indicative of colder climate and more extensive ice-cover.

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  • 30. Andresen, Camilla S.
    et al.
    Karlsson, Nanna B.
    Straneo, Fiammetta
    Schmidt, Sabine
    Andersen, Thorbjørn J.
    Eidam, Emily F.
    Bjørk, Anders A.
    Dartiguemalle, Nicolas
    Dyke, Laurence M.
    Vermassen, Flor
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Gundel, Ida E.
    Sediment discharge from Greenland's marine-terminating glaciers is linked with surface melt2024In: Nature Communications, E-ISSN 2041-1723, Vol. 15, no 1, article id 1332Article in journal (Refereed)
    Abstract [en]

    Sediment discharged from the Greenland Ice Sheet delivers nutrients to marine ecosystems around Greenland and shapes seafloor habitats. Current estimates of the total sediment flux are constrained by observations from land-terminating glaciers only. Addressing this gap, our study presents a budget derived from observations at 30 marine-margin locations. Analyzing sediment cores from nine glaciated fjords, we assess spatial deposition since 1950. A significant correlation is established between mass accumulation rates, normalized by surface runoff, and distance down-fjord. This enables calculating annual sediment flux at any fjord point based on nearby marine-terminating outlet glacier melt data. Findings reveal a total annual sediment flux of 1.324 + /- 0.79 Gt yr-1 over the period 2010-2020 from all marine-terminating glaciers to the fjords. These estimates are valuable for studies aiming to understand the basal ice sheet conditions and for studies predicting ecosystem changes in Greenland's fjords and offshore areas as the ice sheet melts and sediment discharge increase. 

  • 31.
    Ansnaes, Karl-Markus
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Falu gruva och hållbar utveckling2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Falu Copper Mine and Sustainable Development

    Karl-Markus Ansnaes

    Falu copper mine was Sweden’s oldest mine industry which lasted for almost a thousand years. Throughout the history its area has been vastly contaminated by sulfur oxide. The contaminations has created the mining area to an environmental risk zone which has the ability to spread out into the Falu River. The river has its connections to the Dal River which is discharging towards its mouth in the Baltic Sea. In the year 1968 the first measurement from the polluted Falu River took place. Its metal content came from the mining area, although the decontamination expenses were too high for the running company Stora Kopparbergs Bergsslag AB to pay which then led to conflicts with the Environmental Protection Agency of Sweden on terms none of them could agree on. It was not until the year 1983 when they both agreed on a cooperation which contained of continuing measurements until a suffi-cient decontamination method could be applied. The cooperation was named Projekt Falu gruva. The first obligation was to improve the sewage plant in Främby by con-necting the contaminated water from the mining area with the waste water though a chemical treatment. In the year 1987 the treatment successfully began and the same year the Swedish government financed a delegation, called Dalälvsdelegationen, and its purpose was to decontaminate the pollutions along the Dal River. The delegation’s research led to three reports which contained the areas involved in the river’s pollu-tion as well how the mining area would be treated. In 1992 the Country Administra-tive Board of Dalarna, the Environmental Authority of Falun Municipality, the Environ-mental Protection Agency of Sweden and Stora Kopparbergs Bergsslag AB began cooperation in order to treat the polluted area of Falu copper mine. This cooperation became a project called Faluprojektet. The project consisted of three decontamina-tion priorities with different treatments in the area. The first decontamination priority resulted in a reducing amount of the polluted mining water by 80 % in the Falu River. The second and the third decontamination priorities had some issues during its treat-ment due to new environmental laws influenced in 1999 and the recognition from UNESCO as this area was since 2001 a world cultural heritage. Both the law and the recognition stated that it was forbidden to remove the waste on the ground from the area since it was a part of the cultural protection. This meant the waste was removed closer to the mine pit and became part of a slower and natural hydrological treatment which caused the sulfur dioxide penetrating into the ground. By doing this type pf treatment it reflects upon the environmental quality goals which Sweden is aiming for in order to reach for sustainable development.

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  • 32.
    Apler, Anna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Natural Resources and Sustainable Development. Geological Survey of Sweden.
    Kuchler, Magdalena
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Natural Resources and Sustainable Development.
    Zillén, Lovisa
    Division of Marine Environment, Geological Survey of Sweden (SGU).
    Snowball, Ian
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Natural Resources and Sustainable Development.
    The Anthropocene in the northern Baltic Sea – the case of contaminated fiberbanks and implications for sustainable developmentManuscript (preprint) (Other academic)
    Abstract [en]

    The epoch of humankind, the Anthropocene, is usually characterized by the global gaze, which places its focus on global environmental phenomena i.e. global warming and ocean acidification. In this article we argue that the Anthropocene could be better understood with a cross-scalar perspective and present the case of anthropogenic contaminated “fiberbanks” as an example. We present a geological example of the Anthropocene in a Swedish river estuary in the northern Baltic Sea, which hosted nine P&P mills along its’ shores and received large amounts of metal containing wastewater during the 20th century. As a result of the great acceleration and an increased national and global demand for pulp and paper products these fiberbanks formed in shallow waters. As artificial seabed features these thick deposits of contaminated organic-rich material negatively affect the adjacent aquatic environment. By constructing a chemostratigraphy based on sediment cores from accumulation areas and a metal pollution index we show how the aquatic system has recovered from metal pollution. We note, however, that the established stratigraphy fails to identify the fiberbanks, which remain in the shallow zones and are contaminant hotspots. In Sweden, there is an insufficient knowledge of contaminated sediments for a sustainable water and marine management. This knowledge gap in combination with human induced climate changes that may chemically and physically affect sediments and thus, alter dispersion of imbedded pollutants, results in poor understanding and long-term perception of the risks of contaminant dispersion from fiberbanks. We claim that these gaps of knowledge must be filled in order to reach an effective conservation at the same time as a sustainable blue growth in the northern Baltic Sea.

  • 33.
    Ardakani, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Makrofossilanalys av en järnåldersboplats i Gamla Uppsala2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There have been several excavations in Old Uppsala over the years and decades since the area has been inhabited since the Iron Age. The most recent excavation took place in connection with the construction of a railway tunnel, which is a part of the East Link project. The object of an archaeological excavation is to obtain information about the way in which previous civilizations lived in a specific location, what kind of crops were cultivated, what kind of tool were being used, and so forth. In order to obtain information about prehistoric settlements, archaeologists use a variety of different methods. One of these methods is called macrofossil analysis. By using macrofossil analysis, seeds and cereals, in the shape of macrofossils, can be extracted from soil samples. By analysing macrofossils, it is possible to obtain information about buildings and thereby establishing their purposes, for instance residence, barn, and so forth. In this thesis work, macrofossil analysis was used as a way to establish the different functions of three buildings from an Iron Age settlement in Old Uppsala.

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  • 34.
    Ardung, Ola
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Closed To Open Sourve GIS: First Steps In Reverse Engineering ESRI's Layer Defintion File Format2017Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Visualization of digital geographic data is often accomplished through custom symbology that is saved in a proprietary format called a layer file (.lyr). The sharing of free geographical information system (GIS) data can be limited as the symbology data is bound inthe .lyr file format. This makes it harder and more tedious to work with open software tools since it is not possible to convert or open the .lyr file in free and open GIS software and thus limits the distribution of free GIS data. The aim of this thesis is to increase the interoperability of .lyr data between proprietary and free and open GIS software. This was done by revers eengineering the .lyr file format to document the file structure and to distribute the knowledge and metadata gained from this project to the open source community. Reverse engineering the.lyr format provided a well needed metadata and documentation about the format which increases the interoperability and enable future work to continue to lessen the gap between open source and commercial software. This groundwork can therefore, enable a continued development of data interoperability between proprietary and free and open GIS software.

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  • 35.
    Arellano, Santiago
    et al.
    Department of Earth and Space Sciences, Chalmers University of Technology, Gothenburg, Sweden.
    Yalire, M.
    Observatoire Volcanologique de Goma, Centre de Recherche en Sciences Naturelles, Lwiro, Democratic Republic of the Congo.
    Galle, Bo
    Department of Earth and Space Sciences, Chalmers University of Technology, Gothenburg, Sweden.
    Bobrowski, M.
    Institute of Environmental Physics, Heidelberg University, Heidelberg, Germany.
    Dingwell, Adam
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Johansson, M.
    Department of Earth and Space Sciences, Chalmers University of Technology, Gothenburg, Sweden.
    Norman, P.
    Department of Earth and Space Sciences, Chalmers University of Technology, Gothenburg, Sweden.
    Long-term monitoring of SO2 quiescent degassing from Nyiragongo’s lava lake2017In: Journal of African Earth Sciences, ISSN 0899-5362, Vol. 134, p. 866-873Article in journal (Refereed)
    Abstract [en]

    The activity of open-vent volcanoes with an active lava-lake, such as Nyiragongo, is characterized by persistent degassing, thus continuous monitoring of the rate, volume and fate of their gas emissions is of great importance to understand their geophysical state and their potential impact. We report results of SO2 emission measurements from Nyiragongo conducted between 2004 and 2012 with a network of ground-based scanning-DOAS (Differential Optical Absorption Spectroscopy) remote sensors. The mean SO2 emission rate is found to be 13 ± 9 kg s−1, similar to that observed in 1959. Daily emission rate has a distribution close to log-normal and presents large inter-day variability, reflecting the dynamics of percolation of magma batches of heterogeneous size distribution and changes in the effective permeability of the lava lake. The degassed S content is found to be between 1000 and 2000 ppm from these measurements and the reported magma flow rates sustaining the lava lake. The inter-annual trend and plume height statistics indicate stability of a quiescently degassing lava lake during the period of study.

  • 36.
    Asihene, Elvis
    et al.
    Centre for Earth Observation Science (CEOS), University of Manitoba, Winnipeg, Canada.
    Desmond, Durell S.
    Centre for Earth Observation Science (CEOS), University of Manitoba, Winnipeg, Canada.
    Harasyn, Madison L.
    Centre for Earth Observation Science (CEOS), University of Manitoba, Winnipeg, Canada.
    Landry, David
    Centre for Earth Observation Science (CEOS), University of Manitoba, Winnipeg, Canada.
    Veenaas, Cathrin
    Örebro University, School of Science and Technology. Centre for Earth Observation Science (CEOS), University of Manitoba, Winnipeg, Canada.
    Mansoori, Amirbahador
    Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, Canada.
    Fuller, Mark Christopher
    Cryosphere and Climate Research Group, Department of Geography, University of Calgary, Calgary, Canada.
    Stern, Gary
    Centre for Earth Observation Science (CEOS), University of Manitoba, Winnipeg, Canada.
    Barber, David G.
    Centre for Earth Observation Science (CEOS), University of Manitoba, Winnipeg, Canada.
    Gilmore, Colin
    Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, Canada.
    Isleifson, Dustin
    Centre for Earth Observation Science (CEOS) and the Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, Canada.
    Toward the Detection of Oil Spills in Newly Formed Sea Ice Using C-Band Multipolarization Radar2022In: IEEE Transactions on Geoscience and Remote Sensing, ISSN 0196-2892, E-ISSN 1558-0644, Vol. 60, article id 4302615Article in journal (Refereed)
    Abstract [en]

    Oil spills in the Arctic are becoming more likely as shipping traffic increases in response to climate-related sea ice loss. To improve oil spill detection capability, we used a controlled mesocosm to analyze the multipolarized C-band backscatter response of oil in newly formed sea ice (NI). Artificial sea ice was grown in two cylindrical tubs at the Sea-ice Environmental Research Facility, University of Manitoba. The sea ice physical characteristics, including surface roughness, thickness, temperature, and salinity, were measured before and after oil injection below the ice sheet. Time-series C-band radar backscatter measurements detected the differences in the sea ice evolution and oil migration to the sea ice surface in the oil-contaminated tub, which was compared to uncontaminated ice in a control tub. Immediately prior to the presence of oil on the ice surface, the copolarized backscatter is increased by 13-dB local maximum, while the cross-polarized backscatter is decreased by 9-dB. Ice physical properties suggest that the local backscatter maximum and minimum, which occurred immediately before oil migrated onto the surface, were related to a combination of brine and oil upward migration. The findings of this work provide a baseline data interpretation for oil detection in the Arctic Ocean using current and future C-band multipolarization radar satellites.

  • 37.
    Ask, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Kukkonen, Ilmo
    University of Helsinki.
    Olesen, Odleiv
    Geological Survey of Norway.
    Lund, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Fagereng, Åke
    Cardiff University.
    Rutqvist, Jonny
    Lawrence Berkeley National Laboratory.
    Rosberg, Jan-Erik
    Lund University.
    Lorenz, Henning
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Proposed Drilling into Postglacial Faults: The Pärvie Fault System2021In: Glacially-Triggered Faulting / [ed] Holger Steffen, Odleiv Olesen, Raimo Sutinen, Cambridge: Cambridge University Press , 2021, p. 151-174Chapter in book (Refereed)
    Abstract [en]

    Postglacial faults in northern Fennoscandia have been investigated through geophysical methods, trenching, and mapping of brittle deformation structures. Very little is known about postglacial faults through direct measurements. A few short, up to 500 m deep, boreholes exist. Plans for a scientific drilling program were initiated in 2010. The drilling target has been identified: The Pärvie Fault system is the longest known postglacial fault in the world and has been proposed to have hosted an M8 earthquake near the end or just after the last glaciation. Further, this fault system is still microseismically active. The drill sites are north of the Arctic Circle, in a sparsely populated area. Existing site survey data, established logistics, and societal relevance through the fault’s proximity to mining and energy operations make this fault system an appropriate target. The International Continental Scientific Drilling Program approved a full drilling proposal in October 2019. This chapter presents an abbreviated version of the approved proposal.

  • 38.
    Aslani, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Computational and spatial analyses of rooftops for urban solar energy planning2022Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In cities where land availability is limited, rooftop photovoltaic panels (RPVs) offer high potential for satisfying concentrated urban energy demand by using only rooftop areas. However, accurate estimation of RPVs potential in relation to their spatial distribution is indispensable for successful energy planning. Classification, plane segmentation, and spatial analysis are three important aspects in this context. Classification enables extracting rooftops and allows for estimating solar energy potential based on existing training samples. Plane segmentation helps to characterize rooftops by extracting their planar patches. Additionally, spatial analyses enable the identification of rooftop utilizable areas for placing RPVs. This dissertation aims to address some issues associated with these three aspects, particularly (a) training support vector machines (SVMs) in large datasets, (b) plane segmentation of rooftops, and (c) identification of utilizable areas for RPVs. SVMs are among the most potent classifiers and have a solid theoretical foundation. However, they have high time complexity in their training phase, making them inapplicable in large datasets. Two new instance selection methods were proposed to accelerate the training phase of SVMs. The methods are based on locality-sensitive hashing and are capable of handling large datasets. As an application, they were incorporated into a rooftop extraction procedure, followed by plane segmentation. Plane segmentation of rooftops for the purpose of solar energy potential estimation should have a low risk of overlooking superstructures, which play an essential role in the placement of RPVs. Two new methods for plane segmentation in high-resolution digital surface models were thus developed. They have an acceptable level of accuracy and can successfully extract planar segments by considering superstructures. Not all areas of planar segments are utilizable for mounting RPVs, and some factors may further limit their useability. Two spatial methods for identifying RPV-utilizable areas were developed in this realm. They scrutinize extracted planar segments by considering panel installation regulations, solar irradiation, roof geometry, and occlusion, which are necessary for a realistic assessment of RPVs potential. All six proposed methods in this thesis were thoroughly evaluated, and the experimental results show that they can successfully achieve the objectives for which they were designed.

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  • 39. Augustsson, Carita
    et al.
    Rüsing, Tobias
    Niemeyer, Hans
    Kooijman, Ellen
    Swedish Museum of Natural History, Department of Geology.
    Berndt, Jasper
    Bahlburg, Heinrich
    Zimmermann, Udo
    0.3 byr of drainage stability along the Palaeozoic palaeo-Pacific Gondwana margin; a detrital zircon study2015In: Journal of the Geological Society, ISSN 0016-7649, E-ISSN 2041-479X, Vol. 172, p. 186-200Article in journal (Refereed)
    Abstract [en]

    The palaeo-Pacific margin of Gondwana in the present-day south–central Andes is marked by tectonic activity related to subduction and terrane accretion. We present detrital zircon U–Pb data encompassing the Palaeozoic era in northern Chile and northwestern Argentina. Cathodoluminescence images reveal dominantly magmatic zircon barely affected by abrasion and displaying only one growth phase. The main age clusters for these zircon grains are Ediacaran to Palaeozoic with an additional peak at 1.3–0.9 Ga and they can be correlated with ‘Grenvillian’ age, and the Brasiliano, Pampean, and Famatinian orogenies. The zircon data reveal main transport from the nearby Ordovician Famatinian arc and related rocks. The Silurian sandstone units are more comparable with Cambrian units, with Brasiliano and Transamazonian ages (2.2–1.9 Ga) being more common, because the Silurian deposits were situated within or east of the (extinct) Famatinian arc. Hence, the arc acted as a transport barrier throughout Palaeozoic time. The complete suite of zircon ages does not record the accretions of exotic terranes or the Palaeozoic glacial periods. We conclude that the transport system along the palaeo-Pacific margin of Gondwana remained stable for c. 0.3 byr and that provenance data do not necessarily reflect the interior of a continent. Hence, inherited geomorphological features must be taken into account when detrital mineral ages are interpreted.

  • 40.
    Babu, Merin
    Halmstad University, School of Business, Innovation and Sustainability.
    Temporal Analysis of Precipitation and Brownification in Lake Bolmen.2024Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This thesis investigates brownification in Lake Bolmen, Sweden, focusing on the precipitation's effect on water colouration in 3 tributaries to the lake. This study uses long-term meteorological data from the Swedish Meteorological and Hydrological Institute (SMHI) and the water samples collected over more than one year from Lake Bolmen and its three major tributaries Storån, Lillån, and Önnekvarn. Water colour was measured using spectrophotometric techniques. The key findings show a significant positive link between the amount of precipitation per month and water colour, used as a proxy for dissolved organic carbon. The study found that monthly precipitation did not show an immediate effect, but rather that the effect of precipitation on colour was visible with one-month delay. The study finds significant geographical variability in brownification intensity across different streams, indicating that localised effects are also important. The study highlights the crucial role of environmental factors in the organic matter movement and the necessity for specific conservation measures to reduce the negative effects of brownification on water quality. To develop effective Lake Bolmen management techniques, recommendations include continual monitoring and a multidisciplinary approach. This study advances our understanding of the dynamic interplay between freshwater ecosystems hydrology, meteorological, and organic matter processes.

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  • 41.
    Backman, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Geology and Geochemistry.
    Moran, Kathryn
    University of Rhode Island.
    Expanding the Cenozoic paleoceanographic record in the central Arctic Ocean: IODP Expedition 302 synthesis2009In: Central European Journal of Geosciences, E-ISSN 1896-1517, Vol. 1, no 2, p. 157-175Article in journal (Refereed)
    Abstract [en]

    The Arctic Coring Expedition (ACEX) proved to be one of the most transformational missions in almost 40 year of scientific ocean drilling. ACEX recovered the first Cenozoic sedimentary sequence from the Arctic Ocean and extended earlier piston core records from ≈1.5 Ma back to ≈56 Ma. The results have had a major impact in paleoceanography even though the recovered sediments represents only 29% of Cenozoic time. The missing time intervals were primarily the result of two unexpected hiatuses. This important Cenozoic paleoceanographic record was reconstructed from a total of 339 m sediments. The wide range of analyses conducted on the recovered material, along with studies that integrated regional tectonics and geophysical data, produced surprising results including high Arctic Ocean surface water temperatures and a hydrologically active climate during the Paleocene Eocene Thermal Maximum (PETM), the occurrence of a fresher water Arctic in the Eocene, ice-rafted debris as old as middle Eocene, a middle Eocene environment rife with organic carbon, and ventilation of the Arctic Ocean to the North Atlantic through the Fram Strait near the early-middle Miocene boundary. Taken together, these results have transformed our view of the Cenozoic Arctic Ocean and its role in the Earth climate system.

  • 42.
    Bagherbandi, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS. KTH Royal Institute of Technology, Stockholm, Sweden.
    Bai, Yongliang
    School of Geosciences, China University of Petroleum (East China), Qingdao, China.
    Sjöberg, Lars
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Tenzer, Robert
    NTIS - New Technologies for the Information Society, Faculty of Applied Sciences, University of West Bohemia, Plzeň, Czechia.
    Abrehdary, Majid
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Miranda, Silvia
    Departamento de Geofísica y Astronomía, FCEFN Universidad Nacional de San Juan, San Juan, Argentina.
    Sanchez, Juan M. Alcacer
    Departamento de Geofísica y Astronomía, FCEFN Universidad Nacional de San Juan, San Juan, Argentina.
    Effect of the lithospheric thermal state on the Moho interface: a case study in South America2017In: Journal of South American Earth Sciences, ISSN 0895-9811, E-ISSN 1873-0647, Vol. 76, p. 198-207Article in journal (Refereed)
    Abstract [en]

    Gravimetric methods applied for Moho recovery in areas with sparse and irregular distribution of seismic data often assume only a constant crustal density. Results of latest studies, however, indicate that corrections for crustal density heterogeneities could improve the gravimetric result, especially in regions with a complex geologic/tectonic structure. Moreover, the isostatic mass balance reflects also the density structure within the lithosphere. The gravimetric methods should therefore incorporate an additional correction for the lithospheric mantle as well as deeper mantle density heterogeneities. Following this principle, we solve the Vening Meinesz-Moritz (VMM) inverse problem of isostasy constrained by seismic data to determine the Moho depth of the South American tectonic plate including surrounding oceans, while taking into consideration the crustal and mantle density heterogeneities. Our numerical result confirms that contribution of sediments significantly modifies the estimation of the Moho geometry especially along the continental margins with large sediment deposits. To account for the mantle density heterogeneities we develop and apply a method in order to correct the Moho geometry for the contribution of the lithospheric thermal state (i.e., the lithospheric thermal-pressure correction). In addition, the misfit between the isostatic and seismic Moho models, attributed mainly to deep mantle density heterogeneities and other geophysical phenomena, is corrected for by applying the non-isostatic correction. The results reveal that the application of the lithospheric thermal-pressure correction improves the RMS fit of the VMM gravimetric Moho solution to the CRUST1.0 (improves ∼ 1.9 km) and GEMMA (∼1.1 km) models and the point-wise seismic data (∼0.7 km) in South America.

  • 43.
    Bagherbandi, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Eshagh, Mehdi
    Islamic Azad Univ, Dept Surveying.
    Recovery of Moho’s undulations based on the Vening Meinesz–Moritz theory from satellite gravity gradiometry data: A simulation study2012In: Advances in Space Research, ISSN 0273-1177, E-ISSN 1879-1948, Vol. 49, no 6, p. 1097-1111Article in journal (Refereed)
  • 44.
    Bagherbandi, Mohammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences. KTH.
    Jouybari, Arash
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Nilfouroushan, Faramarz
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences. Lantmäteriet.
    Ågren, Jonas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences. Lantmäteriet.
    Importance of precise gravity field modeling in direct georeferencing and aerial photogrammetry: a case study for Sweden2022In: The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XLIII-B2-2022XXIV ISPRS Congress (2022 edition), ISPRS , 2022Conference paper (Refereed)
    Abstract [en]

    Direct georeferencing of airborne mobile mapping systems is developing with unprecedented speed using GNSS/INSintegration. Removal of systematic errors is required for achieving a high accurate georeferenced product in mobile mappingplatforms with integrated GNSS/INS sensors. It is crucial to consider the deflection of verticals (DOV) in direct georeferencing dueto the recently improved INS sensor accuracy. This study determines the DOV using Sweden’s EGM2008 model and gravity data.The influence of the DOVs on horizontal and vertical coordinates and considering different flight heights is assessed. The resultsconfirm that the calculated DOV components using the EGM2008 model are sufficiently accurate for aerial photogrammetrypurposes except for the mountainous areas because the topographic signal is not modeled correctly.

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  • 45.
    Bagriy, Ihor Dmytrovych
    et al.
    Institute of Geological Sciences of the National Academy of Sciences of Ukraine.
    Riepkin, Oleksandr Oleksandrovуch
    Ukrainian Hydrogen Council.
    Zabulonov, Yuriy Leonidovych
    Institute of Environmental Geochemistry of the NAS of Ukraine.
    Vyzhva, Sergiy Andriyovych
    Institute of Geology of Taras Shevchenko Kyiv National University.
    Khrushchev, Dmytro Pavlovуch
    National Academy of Sciences of Ukraine.
    Rusakov, Oleg Maksimovich
    Institute of Geophysics of NAS of Ukraine.
    Popov, Oleksandr Oleksandrovych
    Institute of Geochemistry of the Environment, NAS of Ukraine.
    Maslun, Ninel Volodymyrivna
    Institute of Geological Sciences of the NAS of Ukraine.
    Ivanik, Olena Mykhailivna
    Department of General and Historical Geology, Institute of Geology, Taras Shevchenko National University of Kyiv, Ukraine.
    Kovach, Valeriya Omelanivna
    Institute of Environmental Geochemistry of the NAS of Ukraine.
    Shevchuk, Olena
    Swedish Museum of Natural History, Department of Paleobiology. Ukrainian Academy of Sciences; Stockholm University.
    Kryl, Iaroslav Mykolayovych
    Voden Ukrainy.
    Payuk, Serhii Oleksiyovych
    State Commission of Ukraine on Mineral Reserves.
    Shchurov, Ihor Vyacheslavovуch
    DTEK Naftogaz.
    Hafуch, Ivan Petrovych
    DTEK Naftogaz.
    Leskiv, Ihor Volodymyrovych
    UNGA.
    Rudenko, Yury Fedorovych
    Scientific and Engineering Center of Radio-Hydrogeoecological Polygon Research of the National Academy of Sciences of Ukraine.
    Semenyuk, Volodymyr Grуgorovуch
    Smart Energy.
    Sira, Nataliia Vasilivna
    Ukrainian Geological Research and Production Center.
    Grishanenko, Volodymyr Petrovych
    Center of Oil and Gas Resources.
    Solodkyy, Evgeniy Valeriyovych
    Naftogaz LLC.
    Dubosarsky, Viktor Rudolfovich
    Institute of Geological Sciences of the National Academy of Sciences of Ukraine.
    Dovbysh, Nina Serhiivna
    Institute of Geological Sciences of the NAS of Ukraine.
    Mamyshev, Ihor Evgeniyovych
    Institute of Geological Sciences of the NAS of Ukraine.
    Lihvan, Vadim Maksymovich
    Plativske LLC.
    Kuzmenko, Svyatoslav Oleksandrovich
    Institute of Geological Sciences of the NAS of Ukraine.
    Koval, Anatoly Mykhailovych
    Naftogaz of Ukraine.
    Starodubets, Kyrylо Mykolayovych
    Institute of Geological Sciences of National Academy of Sciences of Ukraine.
    Development and implementation of monitoring of corrosion processes of hydrogen degasation in embrillation zones during the operation of gas pipeline2023In: Environmental and Energy Challenges of the XXI Century. Global Projects. Ways of Implementation / [ed] I.D. Bagriy, Kyiv: Institute of Geological Sciences of the National Academy of Sciences of Ukraine , 2023, p. 254-286Chapter in book (Refereed)
    Abstract [en]

    Pipelines for oil and gas create significant risks of destruction in the systems of industrial and main transportation of hydrocarbons in the presence of corrosion-embrittlement of metal. According to many researchers one of the main reasons for this process is in the area of hydrogen anomalies. It occurs under insulating coating. Insulating coating on the pipeline is peeled off from the metal in such places. Microcracks and pores appear; then moisture spreads to outer surface of the pipe and causes corrosion processes — embrittlement. In addition, it is not excluded that corrosion is intensified due to electrochemical processes and due to undercurrents of gaseous diffusion of hydrogen gas from the mantle strata formed in the areas of the pipeline location. Hydrogen is extremely permeable gas. It leads to swelling, insulation peeling off and defects expanding. The situation creates possibility for moisture penetration to the pipes surface. It also directly affects strength of the metal causing corrosion, cracking and embrittlement. Results of the studies show that embrittlement processes take place mostly in the areas where pipelines pass through oil and gas-bearing structures. In such places hydrogen exits are recorded.

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  • 46.
    Bagriy, Ihor Dmytrovych
    et al.
    Institute of Geological Sciences of the National Academy of Sciences of Ukraine.
    Riepkin, Oleksandr Oleksandrovуch
    Ukrainian Hydrogen Council.
    Zabulonov, Yuriy Leonidovych
    Institute of Environmental Geochemistry of the NAS of Ukraine.
    Vyzhva, Sergiy Andriyovych
    Institute of Geology of Taras Shevchenko Kyiv National University.
    Khrushchev, Dmytro Pavlovуch
    National Academy of Sciences of Ukraine.
    Rusakov, Oleg Maksimovich
    Institute of Geophysics of NAS of Ukraine.
    Popov, Oleksandr Oleksandrovych
    Institute of Geochemistry of the Environment, NAS of Ukraine.
    Maslun, Ninel Volodymyrivna
    Institute of Geological Sciences of the NAS of Ukraine.
    Ivanik, Olena Mykhailivna
    Department of General and Historical Geology, Institute of Geology, Taras Shevchenko National University of Kyiv, Ukraine.
    Kovach, Valeriya Omelanivna
    Institute of Environmental Geochemistry of the NAS of Ukraine.
    Shevchuk, Olena
    Swedish Museum of Natural History, Department of Paleobiology. Ukrainian Academy of Sciences; Stockholm University.
    Kryl, Iaroslav Mykolayovych
    Voden Ukrainy.
    Payuk, Serhii Oleksiyovych
    State Commission of Ukraine on Mineral Reserves.
    Shchurov, Ihor Vyacheslavovуch
    DTEK Naftogaz.
    Hafуch, Ivan Petrovych
    DTEK Naftogaz.
    Leskiv, Ihor Volodymyrovych
    UNGA.
    Rudenko, Yury Fedorovych
    Scientific and Engineering Center of Radio-Hydrogeoecological Polygon Research of the National Academy of Sciences of Ukraine.
    Semenyuk, Volodymyr Grуgorovуch
    Smart Energy.
    Sira, Nataliia Vasilivna
    Ukrainian Geological Research and Production Center.
    Grishanenko, Volodymyr Petrovych
    Center of Oil and Gas Resources.
    Solodkyy, Evgeniy Valeriyovych
    Naftogaz LLC.
    Dubosarsky, Viktor Rudolfovich
    Institute of Geological Sciences of the National Academy of Sciences of Ukraine.
    Dovbysh, Nina Serhiivna
    Institute of Geological Sciences of the NAS of Ukraine.
    Mamyshev, Ihor Evgeniyovych
    Institute of Geological Sciences of the NAS of Ukraine.
    Lihvan, Vadim Maksymovich
    Plativske LLC.
    Kuzmenko, Svyatoslav Oleksandrovich
    Institute of Geological Sciences of the NAS of Ukraine.
    Koval, Anatoly Mykhailovych
    Naftogaz of Ukraine.
    Starodubets, Kyrylо Mykolayovych
    Institute of Geological Sciences of National Academy of Sciences of Ukraine.
    Gas dynamic phenomena (gdf) and causes of accidents at mines2023In: Environmental and Energy Challenges of the XXI Century. Global Projects. Ways of Implementation / [ed] I.D. Bagriy, Kyiv: Institute of Geological Sciences of the National Academy of Sciences of Ukraine , 2023, p. 238-253Chapter in book (Refereed)
    Abstract [en]

    There is a problem of development and implementation of prospecting technology to ensure protection of mining products and prevent disasters during the of coal deposits. It is especially relevant now when issue of environmental protection and improving labor safety in coal mines is very acute. Development of safe search technology for coal deposits is proposed by the authors. It will allow early monitoring to identify places of possible manifestations of gas-dynamic phenomena and make operational decisions for their elimination. The technology is based on application of exploratory gas-geochemical methods for mapping places of accumulation of gas-hydrogen accumulations and their areas. It together with a complex of geological-geophysical method allows to identify areas of possible emergency processes in development zones of mine fields. Feasibility of using search technology to justify use of laying anticipatory degassing wells to prevent uncontrolled explosive processes and technical disasters was proved on large array of conducted field work of planar and profile surveys. The proposed technology was tested on numerous mining sites in the process of exploratory and ecological research in development zones of active and exhausted mine fields.

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  • 47.
    Bagriy, Ihor Dmytrovych
    et al.
    Institute of Geological Sciences of the National Academy of Sciences of Ukraine.
    Riepkin, Oleksandr Oleksandrovуch
    Ukrainian Hydrogen Council.
    Zabulonov, Yuriy Leonidovych
    Institute of Environmental Geochemistry of the NAS of Ukraine.
    Vyzhva, Sergiy Andriyovych
    Institute of Geology of Taras Shevchenko Kyiv National University.
    Khrushchev, Dmytro Pavlovуch
    National Academy of Sciences of Ukraine.
    Rusakov, Oleg Maksimovich
    Institute of Geophysics of NAS of Ukraine.
    Popov, Oleksandr Oleksandrovych
    Institute of Geochemistry of the Environment, NAS of Ukraine.
    Maslun, Ninel Volodymyrivna
    Institute of Geological Sciences of the NAS of Ukraine.
    Ivanik, Olena Mykhailivna
    Department of General and Historical Geology, Institute of Geology, Taras Shevchenko National University of Kyiv, Ukraine.
    Kovach, Valeriya Omelanivna
    Institute of Environmental Geochemistry of the NAS of Ukraine.
    Shevchuk, Olena
    Swedish Museum of Natural History, Department of Paleobiology. Ukrainian Academy of Sciences; Stockholm University.
    Kryl, Iaroslav Mykolayovych
    Voden Ukrainy.
    Payuk, Serhii Oleksiyovych
    State Commission of Ukraine on Mineral Reserves.
    Shchurov, Ihor Vyacheslavovуch
    DTEK Naftogaz.
    Hafуch, Ivan Petrovych
    DTEK Naftogaz.
    Leskiv, Ihor Volodymyrovych
    UNGA.
    Rudenko, Yury Fedorovych
    Scientific and Engineering Center of Radio-Hydrogeoecological Polygon Research of the National Academy of Sciences of Ukraine.
    Semenyuk, Volodymyr Grуgorovуch
    Smart Energy.
    Sira, Nataliia Vasilivna
    Ukrainian Geological Research and Production Center.
    Grishanenko, Volodymyr Petrovych
    Center of Oil and Gas Resources.
    Solodkyy, Evgeniy Valeriyovych
    Naftogaz LLC.
    Dubosarsky, Viktor Rudolfovich
    Institute of Geological Sciences of the National Academy of Sciences of Ukraine.
    Dovbysh, Nina Serhiivna
    Institute of Geological Sciences of the NAS of Ukraine.
    Mamyshev, Ihor Evgeniyovych
    Institute of Geological Sciences of the NAS of Ukraine.
    Lihvan, Vadim Maksymovich
    Plativske LLC.
    Kuzmenko, Svyatoslav Oleksandrovich
    Institute of Geological Sciences of the NAS of Ukraine.
    Koval, Anatoly Mykhailovych
    Naftogaz of Ukraine.
    Starodubets, Kyrylо Mykolayovych
    Institute of Geological Sciences of National Academy of Sciences of Ukraine.
    Justification of global natural, environmental and hydrological conditions of green hydrogen generation, accumulation and logistics ways2023In: Environmental and Energy Challenges of the XXI Century. Global Projects. Ways of Implementation / [ed] I. D. Bagriy, Kyiv: Institute of Geological Sciences of the National Academy of Sciences of Ukraine , 2023, p. 26-95Chapter in book (Refereed)
    Abstract [en]

    The implementation of global energy projectsfor comprehensive solutions to the developmentof energy from renewable sources has all thenecessary conditions for the production, accumulationand transportation of green hydrogenin the south-west of the Odesa region, within theboundaries of the Izmail administrative districtand is timed to the floodplain of the Danube River.

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  • 48.
    Bagriy, Ihor Dmytrovych
    et al.
    Institute of Geological Sciences of the National Academy of Sciences of Ukraine.
    Riepkin, Oleksandr Oleksandrovуch
    Ukrainian Hydrogen Council.
    Zabulonov, Yuriy Leonidovych
    Institute of Environmental Geochemistry of the NAS of Ukraine.
    Vyzhva, Sergiy Andriyovych
    Institute of Geology of Taras Shevchenko Kyiv National University.
    Khrushchev, Dmytro Pavlovуch
    National Academy of Sciences of Ukraine.
    Rusakov, Oleg Maksimovich
    Institute of Geophysics of NAS of Ukraine.
    Popov, Oleksandr Oleksandrovych
    Institute of Geochemistry of the Environment, NAS of Ukraine.
    Maslun, Ninel Volodymyrivna
    Institute of Geological Sciences of the NAS of Ukraine.
    Ivanik, Olena Mykhailivna
    Department of General and Historical Geology, Institute of Geology, Taras Shevchenko National University of Kyiv, Ukraine.
    Kovach, Valeriya Omelanivna
    Institute of Environmental Geochemistry of the NAS of Ukraine.
    Shevchuk, Olena
    Swedish Museum of Natural History, Department of Paleobiology. Ukrainian Academy of Sciences; Stockholm University.
    Kryl, Iaroslav Mykolayovych
    Voden Ukrainy.
    Payuk, Serhii Oleksiyovych
    State Commission of Ukraine on Mineral Reserves.
    Shchurov, Ihor Vyacheslavovуch
    DTEK Naftogaz.
    Hafуch, Ivan Petrovych
    DTEK Naftogaz.
    Leskiv, Ihor Volodymyrovych
    UNGA.
    Rudenko, Yury Fedorovych
    Scientific and Engineering Center of Radio-Hydrogeoecological Polygon Research of the National Academy of Sciences of Ukraine.
    Semenyuk, Volodymyr Grуgorovуch
    Smart Energy.
    Sira, Nataliia Vasilivna
    Ukrainian Geological Research and Production Center.
    Grishanenko, Volodymyr Petrovych
    Center of Oil and Gas Resources.
    Solodkyy, Evgeniy Valeriyovych
    Naftogaz LLC.
    Dubosarsky, Viktor Rudolfovich
    Institute of Geological Sciences of the National Academy of Sciences of Ukraine.
    Dovbysh, Nina Serhiivna
    Institute of Geological Sciences of the NAS of Ukraine.
    Mamyshev, Ihor Evgeniyovych
    Institute of Geological Sciences of the NAS of Ukraine.
    Lihvan, Vadim Maksymovich
    Plativske LLC.
    Kuzmenko, Svyatoslav Oleksandrovich
    Institute of Geological Sciences of the NAS of Ukraine.
    Koval, Anatoly Mykhailovych
    Naftogaz of Ukraine.
    Starodubets, Kyrylо Mykolayovych
    Institute of Geological Sciences of National Academy of Sciences of Ukraine.
    Scientific justification of spatial distribution of hydrogen anomalies in the nearsurface layer of traditional and untraditional oil and gas-bearing structures and implementation of hydrogen search technology2023In: Environmental and Energy Challenges of the XXI Century. Global Projects. Ways of Implementation / [ed] I.D. Bagriy, Kyiv: Institute of Geological Sciences of the National Academy of Sciences of Ukraine , 2023, p. 96-237Chapter in book (Refereed)
    Abstract [en]

    Long-term results of research on mapping of oil and gas-bearing areas on traditional and non-traditional objects (mine fields, shelf areas, astroblems) made it possible to create a database of system criteria for search technology of structural-thermo-atmospheric-hydrologic geochemical research (STAHGR). It is an integral part of methodological solutions complex.There hydrogen was used as the main constituent element of explosives for the first time insearch practice. There are of hydrogen concentrations obtained in the process of research into the mapping features of the oil and gas capacity of traditional and non-traditional HC (hydrocarbons). Their spectrum of research includes H2-hydrogen. Analysis of data results made it possible to single out anomalous single values in areas and in productive areas (in the absence of background) and to conduct detailed, multi-scale studies for the purpose of planar mapping on prospecting works and environmental impacts of gas dynamic phenomena (GDF) during the development of coal massifs.

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  • 49.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Faculty of Engineering – Urmia University, Urmia, Iran.
    Kazemi, Fatemeh
    Mineral Processing, Faculty of Engineering – University of Kashan, Kashan, Iran.
    Abdollahi, Morteza
    Mineral Processing, Faculty of Mining Engineering – Isfahan University of Technology, Isfahan, Iran.
    Mirmohammadi, MirSaleh
    School of Mining Engineering, University of Tehran, Tehran, Tehran, Iran.
    Danesh, Abolfazl
    PhD student of Mineral processing, Faculty of Mining Engineering, Sahand University of Technology, Tabriz, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    The effect of grinding circuit efficiency on the grade and recovery of copper and molybdenum concentrates2022In: Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, ISSN 1556-7036, E-ISSN 1556-7230, Vol. 44, no 3, p. 8121-8134Article in journal (Refereed)
    Abstract [en]

    The efficiency of grinding and flotation process in copper-molybdenum processing circuit, largely affected by performance of thickeners and hydrocyclones devices. The goal of this paper is to investigate the effect of the rate-limiting factors on the performance of these devices and consequently on grinding and separation efficiency of the molybdenum processing circuit. So, a full process mineralogical study have been carried out on outputs of thickeners and hydrocyclone of the molybdenite flotation circuit. According to the results, coarse-grained fractions (>50 μm) of the planar molybdenite will not necessarily be recovered by thickener and hydrocyclones. This is especially true for hydrocyclones when the inlet-load rate is high, i.e., the erroneous discharge of planar molybdenite particles from the overflow of hydrocyclone, as well as their floatability in the thickener overflow, can be attributed to the effect of particle shape and size. This issue harms the grade and recovery of flotation due to the increase in the amount of circulating load (regrinding) and consequently the generation of fine particles (<10 μm) in the hydrocyclone-milling circuit. On the other hand, the almost spherical particles of copper minerals, as well as the nonplanar molybdenite fine-grained particles, are easily removed from the hydrocyclone underflow or settled in thickeners. The introduction of copper mineral particles into molybdenum concentrate and vice versa has reduced the quality of the produced concentrate and undesirable flotation performance.

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  • 50.
    Bailey, Lydia R.
    et al.
    Univ Arizona, USA.
    Drake, Henrik
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Linnaeus University, Linnaeus Knowledge Environments, Water.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Sweden.
    Reiners, Peter W.
    Univ Arizona, USA;Univ Northern British Columbia, Canada.
    Characteristics and Consequences of Red Bed Bleaching by Hydrocarbon Migration: A Natural Example From the Entrada Sandstone, Southern Utah2022In: Geochemistry Geophysics Geosystems, E-ISSN 1525-2027, Vol. 23, no 8, article id e2022GC010465Article in journal (Refereed)
    Abstract [en]

    Extensive regions of yellow and white ("bleached") sandstones within the terrestrial Jurassic red bed deposits of the Colorado Plateau reflect widespread interaction with subsurface reduced fluids which resulted in the dissolution of iron-oxide grain coatings. Reduced fluids such as hydrocarbons, CO2, and organic acids have been proposed as bleaching agents. In this study, we characterize an altered section of the Slick Rock member of the Jurassic Entrada Sandstone that exposes bleached sandstone with bitumen-saturated pore spaces. We observe differences in texture, porosity, mineralogy, and geochemistry between red, pink, yellow, and gray facies. In the bleached yellow facies we observe quartz overgrowths, partially dissolved K-feldspar, calcite cement, fine-grained illite, TiO2-minerals, and pyrite concretions. Clay mineral content is highest at the margins of the bleached section. Fe2O3 concentrations are reduced up to 3x from the red to gray facies but enriched up to 50x in iron-oxide concretions. Metals such as Zn, Pb, and rare-earth elements are significantly enriched in the concretions. Supported by a batch geochemical model, we conclude the interaction of red sandstones with reduced hydrocarbon-bearing fluids caused iron-oxide and K-feldspar dissolution, and precipitation of quartz, calcite, clay, and pyrite. Localized redistribution of iron into concretions can account for most of the iron removed during bleaching. Pyrite and carbonate stable isotopic data suggest the hydrocarbons were sourced from the Pennsylvanian Paradox Formation. Bitumen in pore spaces and pyrite precipitation formed a reductant trap required to produce Cu, U, and V enrichment in all altered facies by younger, oxidized saline brines.

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