Underwater Landslides Triggered by Iceberg Collisions with the Seafloor

Nature Geoscience, June 24

Icebergs originating from the Arctic, Greenland, and Antarctica may cause hazards thousands of kilometers away from their original source by triggering underwater landslides. Four years ago, the bottom edge of an Arctic iceberg scraped against the seafloor, tipped sideways, and broke into two pieces in the Southwind Fjord of Baffin Island. This event triggered a sizable landslide that destabilized two adjacent sedimentary regions of the continental shelf, causing them to partially collapse. The iceberg that triggered the Southwind Fjord landslides was relatively small; but icebergs drifting along continental margins can be ten times larger and reach twenty times deeper, with the lower edge sinking up to 500 meters below the water’s surface. These resulting underwater landslides may have substantial effects on the stability of upper continental slopes, surrounding submarine environments and subsea infrastructure, such as pipelines and communication cables.