An extensive grid of seismic reflection data collected on Ekström Ice Shelf, East Antarctica, between 2010–2018, using an on-ice vibroseis source and snowstreamer, are used to reconstruct the glaciological and tectonic history of this region.
The data clearly image the outcrop and sub-ice extent of the volcanic Explora Wedge (generated through Jurassic rifting and seafloor spreading). The wedge is overlain by a sequence of truncated, dipping marine-sediment layers. The sediment were likely truncated by former ice advance and subsequent retreat; which has also left evidence in the form topographic over-deepening and glacial debris deposits at the sea floor. The debris deposits range from elongated bedforms in a topographic trough (indicating probable former ice-stream flow) to layered sediment wedges at the current ice-shelf front (indicating the likely former extent of grounded ice).
A series of sub-ice shelf geological drilling campaigns in the area will take place (2017-2019) to recover sediments from the sea floor. Combining the topography and material characteristics from vibroseis data with stratigraphic evidence from sediment cores allows a robust reconstruction in this area. Future integration of these results with numerical models will provide a better understanding of past and present interactions between the ice sheet and the solid Earth in Dronning Maud Land, which will in turn improve understanding of future contributions of this region to sea-level rise
