Sediment infill of subglacial meltwater channels on the West Antarctic continental shelf
Subglacial meltwater plays a significant yet poorly understood role in the dynamics of the Antarctic ice sheets. Here we present new swath bathymetry from the western Amundsen Sea Embayment, West Antarctica, showing rneltwater channels eroded into acoustic basement. Their morphological characteristics and size are consistent with incision by subglacial meltwater. To understand how and when these channels formed we have investigated the infill of three channels. Diamictons deposited beneath or proximal to an expanded grounded West Antarctic Ice Sheet are present in two of the channels and these are overlain by glaciomarine sediments deposited after deglaciation. The sediment core from the third channel recovered a turbidite sequence also deposited after the last deglaciation. The presence of deformation till at one core site and the absence of typical meltwater deposits (e.g., sorted sands and gravels) in all three cores suggest that channel incision pre-dates overriding by fast flowing grounded ice during the last glacial period. Given the overall scale of the channels and their incision into bedrock, it is likely that the channels formed over multiple glaciations, possibly since the Miocene, and have been reoccupied on several occasions. This also implies that the channels have survived numerous advances and retreats of grounded ice. (c) 2008 University of Washington. All rights reserved.
Authors: Smith, James A. ORCID record for James A. Smith, Hillenbrand, Claus-Dieter ORCID record for Claus-Dieter Hillenbrand, Larter, Robert D., Graham, Alastair G.C., Kuhn, Gerhard
Privacy & Cookies Policy
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.