Japan's Tsunami Caused Antarctica Iceberg
Scientists have long suspected icebergs to be a link with earthquakes and now a paper published online today in the Journal of Glaciology, marks the first direct observation of the connection between tsunamis and icebergs.
Icebergs can be caused by several things; therefore, when the Tohoku Tsunami occurred in the Pacific Ocean this spring, Burnt and other experts used multiple satellite images to monitor southern polar seas.
From their observations, Burnt, Emile Okal of the Northwestern University and Douglas MacAyeal of the University of Chicago noticed that new icebergs began to float after the sea swell from the tsunami reached Antarctica.
Roughly 18 hours after the earthquake off the coast of Japan hit, the waves from the Tohoku Tsunami rushed towards an ice shelf in Antarctica that is 8,000 miles away. The Sulzberger ice shelf is 260 feet thick and in nearly 50 years has not shifted-that is, not until a 1-foot high wave struck the shelf breaking off massive pieces of ice.
Burnt took a closer look using a synthetic aperture radar data which can penetrate clouds. She discovered images of two moderate-sized icebergs.
According to the report, one of them measured four by six miles in surface area, which is almost the size of Manhattan.
“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.”
The images proved that seismic events could definitely lead to other environmental events across the globe.
“In September 1868, Chilean naval officers reported an unseasonal presence of large icebergs in the southernmost Pacific Ocean, and it was later speculated that they may have calved during the great Arica earthquake and tsunami a month earlier,” Okal said. “We know now that this is a most probable scenario.”