"News about the USAP, the Ice, and the People"
United States Antarctic Program United States Antarctic Program Logo National Science Foundation Logo

Satellite image of ice shelf.
Photo Credit: European Space Agency/Envisat
Icebergs separate from Antarctica's Sulzberger Ice Shelf on March 16 in this satellite image, after waves from the devastating tsunami spawned by an earthquake on March 11 traveled more than 13,000 kilometers. This is the first direct observation of such a connection between tsunamis and icebergs.

Wave action

Japan tsunami linked to iceberg calving in Antarctica

Scientists have linked the earthquake and tsunami that struck Japan in March 2011 with the calving of a Manhattan-sized iceberg from the Sulzberger Ice Shelf more than 13,000 kilometers away in Antarctica.

The finding, detailed in a paper published online in August in the Journal of Glaciology, marks the first direct observation of such a connection between tsunamis and icebergs.

Using multiple satellite images, Kelly Brunt at NASA’s Goddard Space Flight Center External U.S. government site, Emile Okal at Northwestern University External Non-U.S. government site and Douglas MacAyeal at University of Chicago External Non-U.S. government site, were able to observe new icebergs floating off to sea shortly after the sea swell of the tsunami reached Antarctica.

Brunt and MacAyeal are both longtime participants in the U.S. Antarctic Program External U.S. government site, which is funded and managed by the National Science Foundation External U.S. government site. MacAyeal had suggested previously that an Alaskan storm had caused a large Antarctic iceberg to suddenly break apart in 2005.

The swell was likely only about 30 centimeters when it reached the Sulzberger Ice Shelf, but the scientists say the consistency of the waves created enough stress to cause the calving. Lack of sea ice in front of the shelf, which could help dampen the energy of the waves, may have been a factor, according to the scientists.

MacAyeal said in a press release from NASA that the event is more proof of the interconnectedness of Earth systems.

“This is an example not only of the way in which events are connected across great ranges of oceanic distance, but also how events in one kind of Earth system, i.e., the plate tectonic system, can connect with another kind of seemingly unrelated event: the calving of icebergs from Antarctica’s ice sheet,” he said.  

back to top