Published on August 9th, 2011 | by Joshua S Hill
Japanese Tsunami Separates, Breaks Up Antarctic Icebergs
The March 2011 earthquake and tsunami left devastation along the Japanese coast line that is still being felt to this day. But the resultant tsunami also caused havoc in Antarctica, breaking off several large icebergs from the Sulzberger Ice Shelf.
The images were acquired by the Advanced Synthetic Aperture Radar (ASAR) on the European Space Agency’s Envisat satellite, and show how nearly 50 square miles of ice broke off the coast from the waves generated by the Tohoku earthquake.
The waves exploded outward from the epicentre of the Tohoku earthquake, and within 18 hours the waves had travelled 8,000 miles (13,600 kilometers) to the shores of Antarctica.
By the time the waves had reached Antarctica, they were less than a foot in height, but they repeated stress of them were enough to do the damage seen in the video.
The footage is special for a number of reasons. Scientists had long suspected waves could cause an ice shelf to flex and break, but this is the first time that scientists had been able to witness a tsunami affecting an ice shelf. Additionally, scientists usually don’t get to see the footage of an iceberg breaking off; they normally find an iceberg floating off the coast of an ice shelf and have to work back to determine what happened.
That’s why, the moment that Kelly Brunt, a cryosphere specialist at Goddard Space Flight Center in Greenbelt, Md., and colleagues heard of the Japanese earthquake, they looked south.
“In the past, we’ve had calving events where we’ve looked for the source. It’s a reverse scenario — we see a calving and we go looking for a source,” Brunt said. “We knew right away this was one of the biggest events in recent history — we knew there would be enough swell. And this time we had a source.”