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Guido Grosse - One of the best experts on this subject based on the ideXlab platform.
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A synthesis of methane dynamics in Thermokarst lake environments
Earth-Science Reviews, 2020Co-Authors: J.k. Heslop, Guido Grosse, K. M. Walter Anthony, Matthias Winkel, Armando Sepulveda-jauregui, Karla Martinez-cruz, Allen C. Bondurant, Susanne LiebnerAbstract:Abstract Greenhouse gas emissions from physical permafrost thaw disturbance and subsidence, including the formation and expansion of Thermokarst (thaw) lakes, may double the magnitude of the permafrost carbon feedback this century. These processes are not accounted for in current global climate models. Thermokarst lakes, in particular, have been shown to be hotspots for emissions of methane (CH4), a potent greenhouse gas with 32 times more global warming potential than carbon dioxide (CO2) over a 100-year timescale. Here, we synthesize several studies examining CH4 dynamics in a representative first-generation Thermokarst lake (Vault Lake, informal name) to show that CH4 production and oxidation potentials vary with depth in thawed sediments beneath the lake. This variation leads to depth-dependent differences in both in situ dissolved CO2:CH4 ratios and net CH4 production responses to additional warming. Comparing CH4 production, oxidation, and flux values from studies at Vault Lake suggests up to 99% of produced CH4 is oxidized and/or periodically entrapped before entering the atmosphere. We summarize these findings in the context of CH4 literature from Thermokarst lakes and identify future research directions for incorporating Thermokarst lake CH4 dynamics into estimates of the permafrost carbon feedback.
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Past and present Thermokarst lake dynamics in the Yedoma Ice Complex region of North-Eastern Yakutia
2018Co-Authors: Alexandra Veremeeva, Ingmar Nitze, Guido Grosse, Frank Günther, Nadezhda Glushkova, Elizaveta RivkinaAbstract:Thermokarst lakes are typical components of the yedoma-alas dominated relief in the coastal lowlands of North- Eastern Yakutia and formed as a result of thawing Late Pleistocene ice-rich Yedoma Ice Complex (IC) deposits. The aim of our study is to estimate Thermokarst lake area changes from the early Holocene onwards based on RS data. The decrease of Thermokarst lake area from the early Holocene, taking into account total alas depression areas, is as much as 81-83 %. Modern climate warming has led to a general trend of Thermokarst lake area decrease. Lake drainage occurs mostly on elevated sites with high Yedoma IC fraction while lake area increase is typical for low-lying areas with a small Yedoma IC fraction. The area increase of Thermokarst ponds on flat, boggy yedoma surfaces indicates ice wedge degradation in response to rising summer air temperatures and precipitation.
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Variability of Thermokarst-Driven Long-term Thaw Subsidence Across the Arctic
2017Co-Authors: Guido Grosse, Ingmar Nitze, Frank Günther, Benjamin M. Jones, Jens Strauss, L. SchirrmeisterAbstract:Thermokarst is an often non-linear pulse disturbance that rapidly and irreversibly degrades ice-rich permafrost and results in the mobilization of permafrost carbon. Thermokarst landforms occur in most regions with ice-rich permafrost, including the High Arctic, and provide evidence for both past and present permafrost landscape change that can be used to better understand future potential responses. We use high- and medium-resolution optical remote sensing, high-resolution airborne and space-borne digital elevation information, and field data to capture and describe the variability of long-term thaw subsidence and ground deformation due to Thermokarst processes across Arctic permafrost regions. The spatial variability of thaw subsidence associated with various Thermokarst landforms provides information about potential landscape-scale thaw susceptibilities as well as ground ice volumes and distribution. Accordingly, a landscape vulnerability index based on Thermokarst landform morphologies may serve as a proxy for better understanding carbon mobilization potentials. We here exemplarily analyze sites with known near-surface ice-rich deposit thicknesses and where Thermokarst has occurred in the recent and distant past. We assess whether there are correlations between observed thaw subsidence magnitude and its spatial variability in a given area based on depositional environment, Thermokarst age and morphology, and ground ice volume and type. While many of our sites are located in the Yedoma region of Northeast and Central Siberia and Alaska, several others are located in non-Yedoma permafrost regions, such as the Alaska North Slope. The ultimate goal of this study is an observation-based assessment of Thermokarst potential on a panarctic scale as well as contributions to a new panarctic ground ice map.
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A synthesis of Thermokarst and thermo-erosion rates in northern permafrost regions
2016Co-Authors: Guido Grosse, Frank Günther, Daniel J. Hayes, A. B. K. Sannel, Louise M. Farquharson, Benjamin M. Jones, Christopher D Arp, Benjamin W. Abbott, Philip Camill, Torre JorgensonAbstract:Permafrost regions have been identified to host a soil organic carbon (C) pool of global importance, storing more than 1500 PgC. A large portion of this C pool is currently frozen in deep soils and permafrost deposits. Permafrost thaw hence may result in mobilization of large amounts of C as greenhouse gases, dissolved organic C, or particulate organic matter, with substantial impacts on C cycling and C pool distribution. Understanding potential consequences and feedbacks of permafrost degradation therefore requires better quantification of processes and landforms related to thaw. While many predictive land surface models so far consider a gradual increase in the average active layer thickness across the permafrost domain, rapid shifts in landscape topography and surface hydrology caused by thaw of ice-rich permafrost are much more difficult to project. Field studies of Thermokarst and thermo-erosion indicate highly complex and rapid landscape-ecosystem feedbacks. Contrary to top-down permafrost thaw that may affect any permafrost type at the surface, both Thermokarst and thermo-erosion are considered pulse disturbances that are closely linked to presence of near-surface ice-rich permafrost, are active on short sub-annual to decadal time scales, and may affect C stores tens of meters deep. Here we present a comprehensive review synthesizing measured and modeled rates of Thermokarst and thermo-erosion processes from the scientific literature and own observations across the northern Hemisphere permafrost regions. The goal of our synthesis is (1) to provide an overview on the range of Thermokarst and thermo-erosion rates that may be used for parameterization of Thermokarst and thermo-erosion in ecosystem and landscape models; and (2) to assess simple back-of-the-envelope scenarios of the magnitude of C thaw due to Thermokarst and thermo-erosion versus projected active layer thickening. Example scenarios considering Thermokarst lake expansion and talik growth indicate that rapid thaw processes have a high possibility to contribute substantially to permafrost C mobilization over the coming century.
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Impacts of shore expansion and catchment characteristics on lacustrine Thermokarst records in permafrost lowlands, Alaska Arctic Coastal Plain
arktos, 2016Co-Authors: Josefine Lenz, Benjamin M. Jones, Sebastian Wetterich, Natalia Rudaya, Rik Tjallingii, Michael Fritz, Guido GrosseAbstract:Arctic lowland landscapes have been modified by Thermokarst lake processes throughout the Holocene. Thermokarst lakes form as a result of ice-rich permafrost degradation, and they may expand over time through thermal and mechanical shoreline erosion. We studied proximal and distal sedimentary records from a Thermokarst lake located on the Arctic Coastal Plain of northern Alaska to reconstruct the impact of catchment dynamics and morphology on the lacustrine depositional environment and to quantify carbon accumulation in Thermokarst lake sediments. Short cores were collected for analysis of pollen, sedimentological, and geochemical proxies. Radiocarbon and ^210Pb/^137Cs dating, as well as extrapolation of measured historic lake expansion rates, were applied to estimate a minimum lake age of ~1400 calendar years BP. The pollen record is in agreement with the young lake age as it does not include evidence of the “alder high” that occurred in the region ~4000 cal yr BP. The lake most likely initiated from a remnant pond in a drained Thermokarst lake basin (DTLB) and deepened rapidly as evidenced by accumulation of laminated sediments. Increasing oxygenation of the water column as shown by higher Fe/Ti and Fe/S ratios in the sediment indicate shifts in ice regime with increasing water depth. More recently, the sediment source changed as the Thermokarst lake expanded through lateral permafrost degradation, alternating from redeposited DTLB sediments, to increased amounts of sediment from eroding, older upland deposits, followed by a more balanced combination of both DTLB and upland sources. The characterizing shifts in sediment sources and depositional regimes in expanding Thermokarst lakes were, therefore, archived in the Thermokarst lake sedimentary record. This study also highlights the potential for Arctic lakes to recycle old carbon from thawing permafrost and Thermokarst processes.
Frank Günther - One of the best experts on this subject based on the ideXlab platform.
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organic carbon and nitrogen stocks along a Thermokarst lake sequence in arctic alaska
Journal of Geophysical Research, 2019Co-Authors: Ingmar Nitze, Frank Günther, Benjamin M. Jones, Jens Strauss, Josefine Lenz, Matthias Fuchs, Suzanne JockAbstract:Thermokarst lake landscapes are permafrost regions, which are prone to rapid (on seasonal to decadal time scales) changes, affecting carbon and nitrogen cycles. However, there is a high degree of uncertainty related to the balance between carbon and nitrogen cycling and storage. We collected 12 permafrost soil cores from six drained Thermokarst lake basins (DTLBs) along a chronosequence north of Teshekpuk Lake in northern Alaska and analyzed them for carbon and nitrogen contents. For comparison, we included three lacustrine cores from an adjacent Thermokarst lake and one soil core from a non Thermokarst affected remnant upland. This allowed to calculate the carbon and nitrogen stocks of the three primary landscape units (DTLB, lake, and upland), to reconstruct the landscape history, and to analyze the effect of Thermokarst lake formation and drainage on carbon and nitrogen stocks. We show that carbon and nitrogen contents and the carbon-nitrogen ratio are considerably lower in sediments of extant lakes than in the DTLB or upland cores indicating degradation of carbon during Thermokarst lake formation. However, we found similar amounts of total carbon and nitrogen stocks due to the higher density of lacustrine sediments caused by the lack of ground ice compared to DTLB sediments. In addition, the radiocarbon-based landscape chronology for the past 7,000years reveals five successive lake stages of partially, spatially overlapping DTLBs in the study region, reflecting the dynamic nature of ice-rich permafrost deposits. With this study, we highlight the importance to include these dynamic landscapes in future permafrost carbon feedback models. Plain Language Summary When permanently frozen soils (permafrost) contain ice-rich sediments, the thawing of this permafrost causes the surface to sink, which may result in lake formation. This process, the thaw of ice-rich permafrost and melting of ground ice leads to characteristic landforms-known as Thermokarst. Once such a thaw process is initiated in ice-rich sediments, a thaw lake forms and grows by shoreline erosion, eventually expanding until a drainage pathway is encountered and the lake eventually drains, resulting in a drained Thermokarst lake basin. In our study, we show that such a Thermokarst-affected landscape north of Teshekpuk Lake in northern Alaska is shaped by repeated thaw lake formation and lake drainage events during the past 7,000years, highlighting the dynamic nature of these landscapes. These landscape-scale processes have a big effect on the carbon and nitrogen stored in permafrost soils. We show that large amounts of carbon (>45kg C/m(2)) and nitrogen (>2.6kg N/m(2)) are stored in unfrozen lake sediments and in frozen soil sediments. The findings are important when considering the potential effect that permafrost thaw has for the global climate through releasing carbon and nitrogen, which was frozen and therefore locked away for millennia, from the active carbon cycle.
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Past and present Thermokarst lake dynamics in the Yedoma Ice Complex region of North-Eastern Yakutia
2018Co-Authors: Alexandra Veremeeva, Ingmar Nitze, Guido Grosse, Frank Günther, Nadezhda Glushkova, Elizaveta RivkinaAbstract:Thermokarst lakes are typical components of the yedoma-alas dominated relief in the coastal lowlands of North- Eastern Yakutia and formed as a result of thawing Late Pleistocene ice-rich Yedoma Ice Complex (IC) deposits. The aim of our study is to estimate Thermokarst lake area changes from the early Holocene onwards based on RS data. The decrease of Thermokarst lake area from the early Holocene, taking into account total alas depression areas, is as much as 81-83 %. Modern climate warming has led to a general trend of Thermokarst lake area decrease. Lake drainage occurs mostly on elevated sites with high Yedoma IC fraction while lake area increase is typical for low-lying areas with a small Yedoma IC fraction. The area increase of Thermokarst ponds on flat, boggy yedoma surfaces indicates ice wedge degradation in response to rising summer air temperatures and precipitation.
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Variability of Thermokarst-Driven Long-term Thaw Subsidence Across the Arctic
2017Co-Authors: Guido Grosse, Ingmar Nitze, Frank Günther, Benjamin M. Jones, Jens Strauss, L. SchirrmeisterAbstract:Thermokarst is an often non-linear pulse disturbance that rapidly and irreversibly degrades ice-rich permafrost and results in the mobilization of permafrost carbon. Thermokarst landforms occur in most regions with ice-rich permafrost, including the High Arctic, and provide evidence for both past and present permafrost landscape change that can be used to better understand future potential responses. We use high- and medium-resolution optical remote sensing, high-resolution airborne and space-borne digital elevation information, and field data to capture and describe the variability of long-term thaw subsidence and ground deformation due to Thermokarst processes across Arctic permafrost regions. The spatial variability of thaw subsidence associated with various Thermokarst landforms provides information about potential landscape-scale thaw susceptibilities as well as ground ice volumes and distribution. Accordingly, a landscape vulnerability index based on Thermokarst landform morphologies may serve as a proxy for better understanding carbon mobilization potentials. We here exemplarily analyze sites with known near-surface ice-rich deposit thicknesses and where Thermokarst has occurred in the recent and distant past. We assess whether there are correlations between observed thaw subsidence magnitude and its spatial variability in a given area based on depositional environment, Thermokarst age and morphology, and ground ice volume and type. While many of our sites are located in the Yedoma region of Northeast and Central Siberia and Alaska, several others are located in non-Yedoma permafrost regions, such as the Alaska North Slope. The ultimate goal of this study is an observation-based assessment of Thermokarst potential on a panarctic scale as well as contributions to a new panarctic ground ice map.
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A synthesis of Thermokarst and thermo-erosion rates in northern permafrost regions
2016Co-Authors: Guido Grosse, Frank Günther, Daniel J. Hayes, A. B. K. Sannel, Louise M. Farquharson, Benjamin M. Jones, Christopher D Arp, Benjamin W. Abbott, Philip Camill, Torre JorgensonAbstract:Permafrost regions have been identified to host a soil organic carbon (C) pool of global importance, storing more than 1500 PgC. A large portion of this C pool is currently frozen in deep soils and permafrost deposits. Permafrost thaw hence may result in mobilization of large amounts of C as greenhouse gases, dissolved organic C, or particulate organic matter, with substantial impacts on C cycling and C pool distribution. Understanding potential consequences and feedbacks of permafrost degradation therefore requires better quantification of processes and landforms related to thaw. While many predictive land surface models so far consider a gradual increase in the average active layer thickness across the permafrost domain, rapid shifts in landscape topography and surface hydrology caused by thaw of ice-rich permafrost are much more difficult to project. Field studies of Thermokarst and thermo-erosion indicate highly complex and rapid landscape-ecosystem feedbacks. Contrary to top-down permafrost thaw that may affect any permafrost type at the surface, both Thermokarst and thermo-erosion are considered pulse disturbances that are closely linked to presence of near-surface ice-rich permafrost, are active on short sub-annual to decadal time scales, and may affect C stores tens of meters deep. Here we present a comprehensive review synthesizing measured and modeled rates of Thermokarst and thermo-erosion processes from the scientific literature and own observations across the northern Hemisphere permafrost regions. The goal of our synthesis is (1) to provide an overview on the range of Thermokarst and thermo-erosion rates that may be used for parameterization of Thermokarst and thermo-erosion in ecosystem and landscape models; and (2) to assess simple back-of-the-envelope scenarios of the magnitude of C thaw due to Thermokarst and thermo-erosion versus projected active layer thickening. Example scenarios considering Thermokarst lake expansion and talik growth indicate that rapid thaw processes have a high possibility to contribute substantially to permafrost C mobilization over the coming century.
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Evolution of Thermokarst in East Siberian ice-rich permafrost: A case study
Geomorphology, 2013Co-Authors: A. Morgenstern, Frank Günther, I. Fedorova, Mathias Ulrich, Julia Boike, Sebastian Wetterich, Natalia Rudaya, Sebastian Roessler, L. SchirrmeisterAbstract:Thermokarst lakes and basins are major components of ice-rich permafrost landscapes in East Siberian coastal lowlands and are regarded as indicators of regional climatic changes. We investigate the temporal and spatial dynamics of a 7.5 km2, partly drained Thermokarst basin (alas) using field investigations, remote sensing, Geographic Information Systems (GIS), and sediment analyses. The evolution of the Thermokarst basin proceeded in two phases. The first phase started at the Pleistocene/Holocene transition (13 to 12 ka BP) with the initiation of a primary Thermokarst lake on the Ice Complex surface. The lake expanded and persisted throughout the early Holocene before it drained abruptly about 5.7 ka BP, thereby creating a > 20 m deep alas with residual lakes. The second phase (5.7 ka BP to present) is characterized by alternating stages of lower and higher Thermokarst intensity within the alas that were mainly controlled by local hydrological and relief conditions and accompanied by permafrost aggradation and degradation. It included diverse concurrent processes like lake expansion and stepwise drainage, polygonal ice-wedge growth, and the formation of drainage channels and a pingo, which occurred in different parts of the alas. This more dynamic Thermokarst evolution resulted in a complex modern Thermokarst landscape. However, on the regional scale, the changes during the second evolutionary phase after drainage of the initial Thermokarst lakes were less intense than the early Holocene extensive Thermokarst development in East Siberian coastal lowlands as a result of a significant regional change to warmer and wetter climate conditions.
L. Schirrmeister - One of the best experts on this subject based on the ideXlab platform.
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Holocene Thermokarst dynamics in Central Yakutia - A multi-core and robust grain-size endmember modeling approach
Quaternary Science Reviews, 2019Co-Authors: Mathias Ulrich, L. Schirrmeister, Johannes Schmidt, Christine Siegert, Alexander N. Fedorov, Heidrun Matthes, Birgit Schneider, Jens Strauss, Christoph ZielhoferAbstract:Abstract Differentiating Thermokarst basin sediments with respect to the involved processes and environmental conditions is an important tool to understand permafrost landscape dynamics and scenarios and future trajectories in a warming Arctic and Subarctic. Thermokarst basin deposits have complex sedimentary structures due to the variability of Yedoma source sediments, reworking during the Late Glacial to Holocene climate changes, and different stages of Thermokarst history. Here we reconstruct the dynamic growth of Thermokarst lakes and basins and related changes of depositional conditions preserved in sediment sequences using a combination of biogeochemical data and robust grain-size endmember analysis (rEMMA). This multi-proxy approach is used on 10 sediment cores (each 300–400 cm deep) from two key Thermokarst sites to distinguish four time slices that describe the Holocene Thermokarst (lake) basin evolution in Central Yakutia (CY). Biogeochemical proxies and rEMMA reveal fine-grained sedimentation with rather high lake levels and/or reducing conditions, and coarse-grained sedimentation with rather shallow lake levels and/or oxidizing (i.e. terrestrial) conditions in relation to distal and proximal depositional and post-sedimentary conditions. Statistical analysis suggests that the biogeochemical parameters are almost independent of Thermokarst deposit sedimentology. Thus, the biogeochemical parameters are considered as signals of secondary (post-sedimentary) reworking. The rEMMA results are clearly reflecting grain-size variations and depositional conditions. This indicates small-scale varying depositional environments, frequently changing lake levels, and predominantly lateral expansion at the edges of rapidly growing small Thermokarst lakes and basins. These small bodies finally coalesced, forming the large Thermokarst basins we see today in CY. Considering previous paleoenvironmental reconstructions in Siberia, we show the initiation of thaw and subsidence during the Late Glacial to Holocene transition between about 11 and 9 cal kyrs BP, intensive and extensive Thermokarst activity for the Holocene Thermal Maximum (HTM) at about 7 to 5 cal kyrs BP, severely fluctuating water levels and further lateral basin growth between 3.5 cal kyrs BP and 1.5 cal kyrs BP, and the cessation of Thermokarst activity and extensive frost-induced processes (i.e. permafrost aggradation) after about 1.5 cal kyrs BP. However, gradual permafrost warming over recent decades, in addition to human impacts, has led to renewed high rates of subsidence and abrupt, rapid CY Thermokarst processes.
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Variability of Thermokarst-Driven Long-term Thaw Subsidence Across the Arctic
2017Co-Authors: Guido Grosse, Ingmar Nitze, Frank Günther, Benjamin M. Jones, Jens Strauss, L. SchirrmeisterAbstract:Thermokarst is an often non-linear pulse disturbance that rapidly and irreversibly degrades ice-rich permafrost and results in the mobilization of permafrost carbon. Thermokarst landforms occur in most regions with ice-rich permafrost, including the High Arctic, and provide evidence for both past and present permafrost landscape change that can be used to better understand future potential responses. We use high- and medium-resolution optical remote sensing, high-resolution airborne and space-borne digital elevation information, and field data to capture and describe the variability of long-term thaw subsidence and ground deformation due to Thermokarst processes across Arctic permafrost regions. The spatial variability of thaw subsidence associated with various Thermokarst landforms provides information about potential landscape-scale thaw susceptibilities as well as ground ice volumes and distribution. Accordingly, a landscape vulnerability index based on Thermokarst landform morphologies may serve as a proxy for better understanding carbon mobilization potentials. We here exemplarily analyze sites with known near-surface ice-rich deposit thicknesses and where Thermokarst has occurred in the recent and distant past. We assess whether there are correlations between observed thaw subsidence magnitude and its spatial variability in a given area based on depositional environment, Thermokarst age and morphology, and ground ice volume and type. While many of our sites are located in the Yedoma region of Northeast and Central Siberia and Alaska, several others are located in non-Yedoma permafrost regions, such as the Alaska North Slope. The ultimate goal of this study is an observation-based assessment of Thermokarst potential on a panarctic scale as well as contributions to a new panarctic ground ice map.
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Evolution of Thermokarst in East Siberian ice-rich permafrost: A case study
Geomorphology, 2013Co-Authors: A. Morgenstern, Frank Günther, I. Fedorova, Mathias Ulrich, Julia Boike, Sebastian Wetterich, Natalia Rudaya, Sebastian Roessler, L. SchirrmeisterAbstract:Thermokarst lakes and basins are major components of ice-rich permafrost landscapes in East Siberian coastal lowlands and are regarded as indicators of regional climatic changes. We investigate the temporal and spatial dynamics of a 7.5 km2, partly drained Thermokarst basin (alas) using field investigations, remote sensing, Geographic Information Systems (GIS), and sediment analyses. The evolution of the Thermokarst basin proceeded in two phases. The first phase started at the Pleistocene/Holocene transition (13 to 12 ka BP) with the initiation of a primary Thermokarst lake on the Ice Complex surface. The lake expanded and persisted throughout the early Holocene before it drained abruptly about 5.7 ka BP, thereby creating a > 20 m deep alas with residual lakes. The second phase (5.7 ka BP to present) is characterized by alternating stages of lower and higher Thermokarst intensity within the alas that were mainly controlled by local hydrological and relief conditions and accompanied by permafrost aggradation and degradation. It included diverse concurrent processes like lake expansion and stepwise drainage, polygonal ice-wedge growth, and the formation of drainage channels and a pingo, which occurred in different parts of the alas. This more dynamic Thermokarst evolution resulted in a complex modern Thermokarst landscape. However, on the regional scale, the changes during the second evolutionary phase after drainage of the initial Thermokarst lakes were less intense than the early Holocene extensive Thermokarst development in East Siberian coastal lowlands as a result of a significant regional change to warmer and wetter climate conditions.
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Evolution of Thermokarst lakes and alasses in the ice-rich permafrost of the Lena River Delta
2012Co-Authors: A. Morgenstern, Frank Günther, I. Fedorova, Mathias Ulrich, Natalya A Rudaya, Julia Boike, L. SchirrmeisterAbstract:Thermokarst lakes and basins are ubiquitous landforms in arctic lowlands. Current research has a particular focus on Thermokarst processes in ice-rich permafrost deposits in Siberia and the North American Arctic, because these deposits are highly vulnerable to degradation under a warming climate. Their high content of excess ice accounts for their high thawing potential, and the large amount of carbon, which has been stored in these deposits for several thousand years, has a high potential for the release of greenhouse gases. Here, we give a summary of two previous studies on Thermokarst lakes and Thermokarst basins (alasses) in ice-rich permafrost deposits (Ice Complex) of the Lena River Delta. One study reconstructed the Holocene evolution of one particular alas on Kurungnakh Island in the south central Lena Delta until present using field investigations, remote sensing, GIS, and sediment analyses [1]. The other study investigated different Thermokarst stages within the whole Ice Complex extent of the Lena Delta using remote sensing and geoinformation methods to derive information on the potential of future Thermokarst evolution in the study area [2]. The results confirm a widespread Thermokarst development since the transition from Pleistocene to Holocene with the formation of large and deep Thermokarst lakes, which thawed much of the underlying Ice Complex deposits. Most of these large Thermokarst lakes drained partly or completely during the Holocene, thereby leading to a much higher coverage of the study area with alasses (20,0%) than with Thermokarst lakes (5,2%) at present. Subsequent Thermokarst lake development has been restricted and will be restricted in the future. In alasses, residual and secondary Thermokarst lakes can change in their spatial extent depending on hydrological and relief conditions, but are not likely to reach the size of the initial lakes and to substantially rework the adjacent Ice Complex deposits. On Yedoma uplands, the development and growth of primary Thermokarst lakes is limited by shrinking distances to already existing alasses, delta channels, and other topographic lows that foster lake drainage.
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Spatial analyses of Thermokarst lakes and basins in Yedoma landscapes of the Lena Delta
The Cryosphere, 2011Co-Authors: A. Morgenstern, Guido Grosse, Frank Günther, I. Fedorova, L. SchirrmeisterAbstract:Abstract. Distinctive periglacial landscapes have formed in late-Pleistocene ice-rich permafrost deposits (Ice Complex) of northern Yakutia, Siberia. Thermokarst lakes and Thermokarst basins alternate with ice-rich Yedoma uplands. We investigate different Thermokarst stages in Ice Complex deposits of the Lena River Delta using remote sensing and geoinformation techniques. The morphometry and spatial distribution of Thermokarst lakes on Yedoma uplands, Thermokarst lakes in basins, and Thermokarst basins are analyzed, and possible dependence upon relief position and cryolithological context is considered. Of these Thermokarst stages, developing Thermokarst lakes on Yedoma uplands alter ice-rich permafrost the most, but occupy only 2.2% of the study area compared to 20.0% occupied by Thermokarst basins. The future potential for developing large areas of Thermokarst on Yedoma uplands is limited due to shrinking distances to degradational features and delta channels that foster lake drainage. Further Thermokarst development in existing basins is restricted to underlying deposits that have already undergone thaw, compaction, and old carbon mobilization, and to deposits formed after initial lake drainage. Future Thermokarst lake expansion is similarly limited in most of Siberia's Yedoma regions covering about 106 km2, which has to be considered for water, energy, and carbon balances under warming climate scenarios.
Daniel Mege - One of the best experts on this subject based on the ideXlab platform.
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evolution of the banks of Thermokarst lakes in central yakutia central siberia due to retrogressive thaw slump activity controlled by insolation
Geomorphology, 2015Co-Authors: A Sejourne, F Costard, A A Fedorov, Julien Gargani, J Skorve, M Masse, Daniel MegeAbstract:Abstract As observed in most regions in the Arctic, the thawing of ice-rich permafrost (Thermokarst) has been developing in Central Yakutia. However, the relationship between Thermokarst development and climate variations is not well understood in this region, in particular the development rate of thaw slumps. The objective of this paper is to understand the current development of Thermokarst by studying the evolution of the banks of Thermokarst lakes. We studied retrogressive thaw slumps and highly degraded ice-wedge polygons (baydjarakhs), indicative of Thermokarst, using high resolution satellite images taken in 2011–2013 and conducting field studies. The retrogressive thaw slump activity results in the formation of thermocirque with a minimum and maximum average headwall retreat of 0.5 and 3.16 m·yr − 1 respectively. The thermocirques and the baydjarakhs are statistically more concentrated on the south- to southwest-facing banks of Thermokarst lakes. Moreover, the rate of headwall retreat of the thermocirques is the most important on the south-facing banks of the lakes. These observations indicate a control of the current permafrost thaw on the banks of Thermokarst lakes by insolation. In the context of recent air temperature increase in Central Yakutia, the rate of thermocirque development may increase in the future.
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Evolution of the banks of Thermokarst lakes in Central Yakutia (Central Siberia) due to retrogressive thaw slump activity controlled by insolation
Geomorphology, 2015Co-Authors: A Sejourne, F Costard, A A Fedorov, Julien Gargani, J Skorve, M Masse, Daniel MegeAbstract:As observed in most regions in the Arctic, the thawing of ice-rich permafrost (Thermokarst) has been developing in Central Yakutia. However, the relationship between Thermokarst development and climate variations is not well understood in this region, in particular the development rate of thaw slumps. The objectives of this paper are to understand the current development of Thermokarst by studying the evolution of the banks of Thermokarst lakes. We studied retrogressive thaw slumps and highly degraded ice-wedge polygons (baydjarakhs), indicative of Thermokarst, using high resolution satellite images taken in 2011–2013 and conducting field studies. The retrogressive thaw slump activity results in the formation of thermocirque with a minimum and maximum average headwall retreat of 0.5 and 3.16 m.yr− 1 respectively. The thermocirques and the baydjarakhs are statistically more concentrated on the south- to southwest-facing banks of Thermokarst lakes. Moreover, the rate of headwall retreat of the thermocirques is the most important on the south-facing banks of the lakes. These observations indicate a control of the current permafrost thaw on the banks of Thermokarst lakes by insolation. In the context of recent air temperature increase in Central Yakutia, the rate of thermocirque development may increase in the future.
A Sejourne - One of the best experts on this subject based on the ideXlab platform.
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evolution of the banks of Thermokarst lakes in central yakutia central siberia due to retrogressive thaw slump activity controlled by insolation
Geomorphology, 2015Co-Authors: A Sejourne, F Costard, A A Fedorov, Julien Gargani, J Skorve, M Masse, Daniel MegeAbstract:Abstract As observed in most regions in the Arctic, the thawing of ice-rich permafrost (Thermokarst) has been developing in Central Yakutia. However, the relationship between Thermokarst development and climate variations is not well understood in this region, in particular the development rate of thaw slumps. The objective of this paper is to understand the current development of Thermokarst by studying the evolution of the banks of Thermokarst lakes. We studied retrogressive thaw slumps and highly degraded ice-wedge polygons (baydjarakhs), indicative of Thermokarst, using high resolution satellite images taken in 2011–2013 and conducting field studies. The retrogressive thaw slump activity results in the formation of thermocirque with a minimum and maximum average headwall retreat of 0.5 and 3.16 m·yr − 1 respectively. The thermocirques and the baydjarakhs are statistically more concentrated on the south- to southwest-facing banks of Thermokarst lakes. Moreover, the rate of headwall retreat of the thermocirques is the most important on the south-facing banks of the lakes. These observations indicate a control of the current permafrost thaw on the banks of Thermokarst lakes by insolation. In the context of recent air temperature increase in Central Yakutia, the rate of thermocirque development may increase in the future.
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Evolution of the banks of Thermokarst lakes in Central Yakutia (Central Siberia) due to retrogressive thaw slump activity controlled by insolation
Geomorphology, 2015Co-Authors: A Sejourne, F Costard, A A Fedorov, Julien Gargani, J Skorve, M Masse, Daniel MegeAbstract:As observed in most regions in the Arctic, the thawing of ice-rich permafrost (Thermokarst) has been developing in Central Yakutia. However, the relationship between Thermokarst development and climate variations is not well understood in this region, in particular the development rate of thaw slumps. The objectives of this paper are to understand the current development of Thermokarst by studying the evolution of the banks of Thermokarst lakes. We studied retrogressive thaw slumps and highly degraded ice-wedge polygons (baydjarakhs), indicative of Thermokarst, using high resolution satellite images taken in 2011–2013 and conducting field studies. The retrogressive thaw slump activity results in the formation of thermocirque with a minimum and maximum average headwall retreat of 0.5 and 3.16 m.yr− 1 respectively. The thermocirques and the baydjarakhs are statistically more concentrated on the south- to southwest-facing banks of Thermokarst lakes. Moreover, the rate of headwall retreat of the thermocirques is the most important on the south-facing banks of the lakes. These observations indicate a control of the current permafrost thaw on the banks of Thermokarst lakes by insolation. In the context of recent air temperature increase in Central Yakutia, the rate of thermocirque development may increase in the future.
