Documentation of sediment cores

DOI

The presence of a complex bedform arrangement on the sea-floor of the continental shelf in the western Amundsen Sea Embayment, West Antarctica, indicates a multi-temporal record of flow related to the activity of one or more ice streams in the past. Mapping and division of the bedforms into distinct landform assemblages reveals their time-transgressive history, which implies that bedforms can neither be considered part of a single down-flow continuum nor a direct proxy for palaeo-ice velocity, as suggested previously. A main control on the bedform imprint is the geology of the shelf, which is divided broadly between rough bedrock on the inner shelf, and smooth, dipping sedimentary strata on the mid-to-outer shelf. Inner shelf bedform variability is well preserved, revealing information about local, complex basal-ice conditions, meltwater flow, and ice dynamics over time. These details, which are not apparent at the scale of regional morphological studies, indicate that past ice streams flowed across the entire shelf, at times, and often had onset zones that lay within the interior of the Antarctic Ice Sheet today. In contrast, highly elongated subglacial bedforms on sedimentary strata of the middle to outer shelf represent a timeslice snapshot of the last activity of ice-stream flow, and may be a truer representation of fast palaeo-ice flow in these locations. A revised model for ice streams on the shelf captures complicated multi-temporal bedform patterns associated with an Antarctic palaeo-ice stream for the first time, and confirms a strong substrate control on this ice stream system that drained the West Antarctic Ice Sheet during the Late Quaternary.

Identifier
DOI https://doi.org/10.1594/PANGAEA.724192
Related Identifier https://doi.org/10.1016/j.quascirev.2009.07.003
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.724192
Provenance
Creator Graham, Alastair G C ORCID logo; Larter, Robert D ORCID logo; Gohl, Karsten ORCID logo; Hillenbrand, Claus-Dieter ORCID logo; Smith, James A ORCID logo; Kuhn, Gerhard ORCID logo
Publisher PANGAEA
Publication Year 2009
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Publication Series of Datasets; Collection
Format application/zip
Size 15 datasets
Discipline Earth System Research
Spatial Coverage (-118.486W, -74.302S, -110.265E, -72.764N); Amundsen Sea
Temporal Coverage Begin 2006-03-01T18:01:00Z
Temporal Coverage End 2006-03-10T22:51:00Z