The first Ross Sea – Amundsen Sea transect: A stratigraphic correlation of deep sea seismic reflection data along the Pacific margin of West Antarctica

• Main Authors: Lindeque, Ansa, Gohl, Karsten, Uenzelmann-Neben, Gabriele, Davy, Bryan
• Format: Conference Object
• Language: unknown
• Published: 2011
• Subjects: Amundsen Sea; Antarc*; Antarctic; Antarctica; Bellingshausen Sea; Ice Sheet; Ross Sea; West Antarctica
• Online Access: https://epic.awi.de/id/eprint/25848/; http://www.isaes2011.org.uk/programme.html; https://hdl.handle.net/10013/epic.39497

We recently acquired a continuous set of multichannel seismic reflection profiles off the Pacific margin of West Antarctica, in order to link the seismic network of the Amundsen Sea with that of the Ross Sea. An approximate 2000 km long transect within the dataset, now enables the first regional stratigraphic correlation of major seismic horizons across the Ross Sea – Amundsen Sea – Bellingshausen Sea region. This stratigraphic correlation presents a foundation for understanding deep sea sediment supply before and since the first advances of the Western Antarctic ice sheet to the continental shelf. At least three high amplitude reflectors are prominent along the entire transect length. These are mostly horizontal, continuous and undisturbed, and interpreted to represent depositional processes driven by pre-glacial, transitional, and glacially dominated regimes. A clear basement reflection can be traced along the entire transect at 6 to 8 s TWT, and its morphology varies from rugged to smooth. We observe a minimum total sediment thickness of 0.6 s two-way-time (TWT) over a basement high in front of the Ross Sea, and maximum total sediment thickness, of 2.6 s TWT (~ 3-4 km thick) near the centre of the transect, corresponding to a basement low in the Amundsen Sea. Although our derived stratigraphic model is limited due to the absence of boreholes, it provides a framework for understanding the dynamics and distribution of sediments from the two major Pacific glacial outlet basins into the deep sea.