Climate-controlled submarine landslides on the Antarctic continental margin

International Ocean Discovery Program (IODP) Expedition 374
Ross Sea Continental Ice Shelf, Antarctica
Funded by: Natural Environment Research Council (NERC)
Date: 2023
Principal Investigator: Dr Jenny Gales , Associate Professor in Hydrography and Ocean Exploration
Part of the International Ocean Discovery Program Expedition 374 (2018–2023), led by Professor Rob McKay, Director of the Antarctic Research Centre at Victoria University of Wellington, Laura De Santis, a researcher at the National Institute of Oceanography and Applied Geophysics.
 
Antarctica's continental margins pose a potential tsunami risk to the Southern Hemisphere that could be caused by submarine landslides. Dr Jenny Gales and the team looked at the major submarine landslides compiled along the eastern Ross Sea continental slope to understand the factors driving slope failure and provide evidence to assess future geohazards. They identified:
  • weak layers beneath three submarine landslides, consisting of interbedded Miocene-to-Pliocene-age diatom oozes and glaciomarine diamicts.
  • the lithological difference – coming from glacial-to-interglacial variations in biological productivity, ice proximity and ocean circulation – saw changes in sediment deposition causing preconditioned slope failure
  • recurrent Antarctic submarine landslides were likely triggered by seismicity associated with glacioisostatic readjustment.
Ongoing climate warming and ice retreat may increase regional glacioisostatic seismicity, triggering Antarctic submarine landslides.