Japan tsunami linked to iceberg calving in Antarctica
Posted August 12, 2011
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 , Emile Okal at Northwestern University and Douglas MacAyeal at University of Chicago , 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 , which is funded and managed by the National Science Foundation . 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.