Results 21 to 30 of about 7,742 (217)

Sea level fluctuations and their signature in the composition and structure of polygonal wedge ice in the Yenisei River lower reaches

Лëд и снег, 2015
Late Pleistocene and Holocene polygonal-wedge ice is studied in the lower course of the Yenisei River. Ice distribution, features of the formation, chemical and microbiological composition were determined.
O. L. Opokina, E. A. Slagoda, I. B. Tomberg, M. Yu. Suslova, A. D. Firsova, T. V. Khodzher, N. A. Zhuchenko   +6 more
doaj   +1 more source

Spatial variability of CO₂ uptake in polygonal tundra: assessing low-frequency disturbances in eddy covariance flux estimates [PDF]

Biogeosciences, 2017
The large spatial variability in Arctic tundra complicates the representative assessment of CO2 budgets. Accurate measurements of these heterogeneous landscapes are, however, essential to understanding their vulnerability to climate change.
N. Pirk, N. Pirk, J. Sievers, J. Mertes, J. Mertes, F.-J. W. Parmentier, M. Mastepanov, M. Mastepanov, T. R. Christensen, T. R. Christensen   +9 more
doaj   +1 more source

Coupling of Finite Element Method and Peridynamics to Simulate Ship-Ice Interaction

Journal of Marine Science and Engineering, 2023
In this work, the finite element method (PD-FEM) coupling strategy is used to simulate ship-ice interaction. Two numerical benchmark tests are selected to validate the coupling approach and its program.
Renwei Liu, Yanzhuo Xue, Xikui Lu
doaj   +1 more source

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

Structural insights into an engineered feruloyl esterase with improved MHET degrading properties

FEBS Letters, EarlyView.
A feruloyl esterase was engineered to mimic key features of MHETase, enhancing the degradation of PET oligomers. Structural and computational analysis reveal how a point mutation stabilizes the active site and reshapes the binding cleft, expading substrate scope.
Panagiota Karampa, Konstantinos Makryniotis, Theofani‐Iosifina Sousani, Evangelos Topakas, Vangelis Daskalakis, Maria Dimarogona   +5 more
wiley   +1 more source