Seismostratigraphic and Geomorphic Evidence for the Glacial History of the Northwestern Chukchi Margin, Arctic Ocean


Contact
skwan [ at ] kopri.re.kr

Abstract

High-resolution seafloor mapping provides insights into the dynamics of past ice sheets/ice shelves on high-latitude continental margins. Geological/geophysical studies in the Arctic Ocean suggest widespread Pleistocene ice grounding on the Chukchi–East Siberian continental margin. However, flow directions, timing, and behavior of these ice masses are not yet clear due to insufficient data. We present a combined seismostratigraphic and morphobathymetric analysis of the Chukchi Rise off the northwestern Chukchi margin using the densely acquired subbottom profiler (SBP) and multibeam echosounder (MBES) data. Comparison with deeper airgun seismic records shows that the SBP data cover most of the glaciogenic stratigraphy possibly spanning ca. 0.5–1Ma. Based on the stratigraphic distribution and geometry of acoustically transparent glaciogenic diamictons, the lateral and vertical extent of southern- sourced grounded ice became smaller over time. The older deposits are abundant as debris lobes on the slope contributing to a large trough mouth fan, whereas younger grounding-zone wedges are found at shallower depths. MBES data show two sets of mega-scale lineations indicating at least two fast ice- streaming events of different ages. Contour-parallel recessional morainic ridges mark a stepwise retreat of the grounded ice margin, likely controlled by rising sea levels during deglaciation(s). The different inferred advance and retreat directions of the southern-sourced ice reflect complex geomorphic settings. The overall picture shows that the Chukchi Rise was an area where different ice streams had complex interactions. In addition to glaciogenic deposits, we identify a number of related or preceding seabed features including mounds, gullies/channels, and sediment waves.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Helmholtz Cross Cutting Activity (2021-2027)
N/A
Peer revision
ISI/Scopus peer-reviewed
Publication Status
Published
Eprint ID
54417
DOI 10.1029/2020JF006030

Cite as
Kim, S. , Polyak, L. , Young, J. J. , Niessen, F. , Kim, H. J. , Choi, Y. , Kang, S. G. , Hong, J. K. , Nam, S. I. and Jin, Y. K. (2021): Seismostratigraphic and Geomorphic Evidence for the Glacial History of the Northwestern Chukchi Margin, Arctic Ocean , Journal of Geophysical Research: Earth Surface, 126 , pp. 1-29 . doi: 10.1029/2020JF006030


Share


Citation

Geographical region

Research Platforms
N/A

Campaigns
N/A


Actions
Edit Item Edit Item