For the first time, a NASA scientist and her colleagues were able to detect the power of an earthquake and tsunami to break off large icebergs a hemisphere away.
Kelly Brunt, a cryosphere specialist at Goddard Space Flight Center, Greenbelt, Md including colleagues were able to connect the calving of icebergs from the Sulzberger Ice Shelf in Antarctica, following the Tohoku Tsunami, which originated with an earthquake off the coast of Japan in March 2011.
The finding, detailed in a paper published online in the Journal of Glaciology, marks the first direct observation of such a link between tsunamis and icebergs.
The birth of an iceberg can come about in many ways. Oftentely, scientists will watch the towering, frozen monoliths break into the polar seas and work backwards to figure out the cause. So on March 11 this spring, when the Tohoku Tsunami was triggered in the Pacific Ocean, Brunt and colleagues immediately looked south. All the way south, using multiple satellite images, Brunt, 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.
The dynamics of this event in perspective, An earthquake off the coast of Japan caused huge waves to explode from the epicenter. Increases of water, it was swarming to the ice shelf in Antarctica, 8,000 miles (13,600 kilometers) away, and came about 18 hours after the earthquake, the waves broke on several pieces of ice, corresponding to about twice the combined area of Manhattan. According to historical records of this particular piece of ice had not moved at least 46 years before the tsunami came.
And when all was done, scientists were able to observe the ice shelves in Antarctica as close to real time, such as satellite imagery allows, and a preview of a new iceberg floating off the Ross Sea .
Scientists in the 1970s, the deviation of ice shelves speculated on several occasions, a floating extension of a glacier or ice that is on earth – could break the waves of icebergs. The scientific papers in recent years and models level measurements in an attempt to quantify the effects of waves on several fronts ice shelf.
The swell was probably about a foot tall (30 cm) when he reached the Sulzberger shelf. But the consistency of the waves generated stress enough to cause calving. This particular piece of floating ice shelf is about 260 feet (80 meters) thick, from its exposed surface, base submerged.
When the earthquake occurred, Okal immediately honed in the faces of the Antarctic continent vulnerable. With the knowledge of iceberg calving and showed what a model of NOAA’s tsunami on the projected path unobstructed ocean and South Pacific, Okal, MacAyeal Brunt and started to look at what is called the ice shelf Sulzberger. The bay faces Sulzberger Sulzberger Bay and New Zealand.