Results 31 to 40 of about 71,705 (309)

Monitoring Arctic permafrost – examining the contribution of volunteered geographic information to mapping ice-wedge polygons [PDF]

The Cryosphere
This study evaluates the potential of Volunteered Geographic Information (VGI) for mapping and monitoring ice-wedge polygons in Arctic permafrost regions through two case studies in Alaska and Canada.
P. Walz, O. Fritz, S. Marx, M. M. Mueller, C. Thiel, J. Lenz, S. Kaiser, R. Frappier, A. Zipf, A. Zipf, M. Langer, M. Langer   +11 more
doaj   +1 more source

Yedoma Cryostratigraphy of Recently Excavated Sections of the CRREL Permafrost Tunnel Near Fairbanks, Alaska

Frontiers in Earth Science, 2022
Recent excavation in the new CRREL Permafrost Tunnel in Fox, Alaska provides a unique opportunity to study properties of Yedoma — late Pleistocene ice- and organic-rich syngenetic permafrost.
Mikhail Kanevskiy, Yuri Shur, Nancy H. Bigelow, Kevin L. Bjella, Thomas A. Douglas, Daniel Fortier, Benjamin M. Jones, M. Torre Jorgenson   +7 more
doaj   +1 more source

Cumulative impacts of a gravel road and climate change in an ice-wedge-polygon landscape, Prudhoe Bay, Alaska

Arctic Science, 2022
Environmental impact assessments for new Arctic infrastructure do not adequately consider the likely long-term cumulative effects of climate change and infrastructure to landforms and vegetation in areas with ice-rich permafrost, due in part to lack of ...
Donald A. Walker, Martha K. Raynolds, Mikhail Z. Kanevskiy, Yuri S. Shur, Vladimir E. Romanovsky, Benjamin M. Jones, Marcel Buchhorn, M. Torre Jorgenson, Jozef Šibík, Amy L. Breen, Anja Kade, Emily Watson-Cook, Georgy Matyshak, Helena Bergstedt, Anna K. Liljedahl, Ronald P. Daanen, Billy Connor, Dmitry Nicolsky, Jana L. Peirce   +18 more
doaj   +1 more source

Reconstruction of average January temperatures during the early Holocene in the North-East of the Bolshezemelskaya tundra

Лëд и снег, 2020
The aim of the study was to establish the period of accumulation of peatland with ice wedges near Vorkuta town based on series of calibrated radiocarbon dates, to anchor in time the isotope-oxygen curve of syngenetic ice wedge from peatland and to ...
N. A. Budantseva, Yu. K. Vasil'chuk
doaj   +1 more source

A Numerical Simulation Method for Investigating the Fluid–Structure–Ice Coupling Mechanism of a Wedge Breaking through Ice into Water

Applied Sciences
We aimed to investigate the fluid–solid–ice coupling mechanism as structures break through ice into water. Using LS–DYNA finite element software, a numerical simulation method is established, based on the ALE flow–solid coupling method, and the penalty ...
Fucun Wang, Yongyi Lu, Zhiqing Zhao, Bingsen Qiu, Lixiao Mu, Xiaoyu Wang, Yeqing Jin   +6 more
doaj   +1 more source

Dissolved organic carbon loss from Yedoma permafrost amplified by ice wedge thaw

Environmental Research Letters, 2013
Pleistocene Yedoma permafrost contains nearly a third of all organic matter (OM) stored in circum-arctic permafrost and is characterized by the presence of massive ice wedges.
J E Vonk, P J Mann, K L Dowdy, A Davydova, S P Davydov, N Zimov, R G M Spencer, E B Bulygina, T I Eglinton, R M Holmes   +9 more
doaj   +1 more source

Deep Convolutional Neural Networks for Automated Characterization of Arctic Ice-Wedge Polygons in Very High Spatial Resolution Aerial Imagery

Remote Sensing, 2018
The microtopography associated with ice-wedge polygons governs many aspects of Arctic ecosystem, permafrost, and hydrologic dynamics from local to regional scales owing to the linkages between microtopography and the flow and storage of water, vegetation
Weixing Zhang, Chandi Witharana, Anna K. Liljedahl, Mikhail Kanevskiy   +3 more
doaj   +1 more source

Numerical modeling of two-dimensional temperature dynamics across ice-wedge polygons [PDF]

, 2017
Thesis (M.S.) University of Alaska Fairbanks, 2017The ice wedges on the North Slope of Alaska have been forming for many millennia, when the ground cracked and the cracks were filled with snowmelt water.
Garayshin, Viacheslav Valer'evich, Гарайшин, Вячеслав Валерьевич   +1 more
core  

Evolving fracture patterns: columnar joints, mud cracks, and polygonal terrain [PDF]

, 2013
When cracks form in a thin contracting layer, they sequentially break the layer into smaller and smaller pieces. A rectilinear crack pattern encodes information about the order of crack formation, as later cracks tend to intersect with earlier cracks at ...
Goehring, Lucas
core   +2 more sources

The (Glg)ABCs of cyanobacteria: modelling of glycogen synthesis and functional divergence of glycogen synthases in Synechocystis sp. PCC 6803

FEBS Letters, EarlyView.
We reconstituted Synechocystis glycogen synthesis in vitro from purified enzymes and showed that two GlgA isoenzymes produce glycogen with different architectures: GlgA1 yields denser, highly branched glycogen, whereas GlgA2 synthesizes longer, less‐branched chains.
Kenric Lee, Dimitrios Bekiari, Sofia Doello, Karl Forchhammer   +3 more
wiley   +1 more source