Giant Submarine Landslide on the East Antarctic Margin During the Plio-Pleistocene

A giant submarine landslide complex is reported on the George V margin of East Antarctic continental rise. Such landslides are imaged on seismic profiles that display evidence of basal glide planes and headwall scarps. A longitudinal seismic transect, and correlation to nearby drill sites suggest the slide was formed after the early Pliocene. To our knowledge, it is the largest submarine landslide ever identified on the Antarctic margin, with approximately 2,300 km³ of sediments evacuated from the shelf. We propose potential triggers for this slide, including weak layers, fluid and isostatic rebound following ice sheet retreat, although hypothesis relating to the processes has to be tested by direct stratigraphic data. Given the size of the landslide, an improved understanding of whether it was formed during a single event or more gradually during a prolonged interval is critical to evaluate whether Antarctic submarine geohazards may exist in a rapidly changing climates.