This year researchers witnessed for the first time evidence of an ice mass separation triggered by a tsunami. Until this discovery scientists could only speculate this was possible. The large mass of ice separated from the coast of Antarctica on a part of the continent called the Sulzberger Ice Shelf. The Tohoku earthquake and tsunami that struck Japan in March of this year also generated sea swell that propagated throughout the Pacific basin, as seen in this model. Within 18 hours the first series of waves bombarded the ice shelf, located 8,000 miles away, ultimately resulting in a mass of ice 50 square miles in size being shed from the continent. Evidence of the separation was first observed in images captured by NASA's Aqua and Terra satellites. Looking through a hole in the clouds, researches spotted a single iceberg roughly the size of Manhattan, drifting off the coast of the ice shelf. Using radar imagery from a European Space Agency satellite, scientists discovered not only one, but two large icebergs, along with several smaller pieces of ice that had separated from the continent. An aerial photo from the USGS archive dating back to 1965 shows the area of the ice shelf that separated had been intact for more than 46 years. The separation occured at a time of year when sea ice around the continent is at a minumum; suggesting sea ice may play a critical role in ice shelf stability.