The
tsunami that devastated the northeast coast of Japan on March 11th was
created by at least two wave fronts that merged to form a far more
destructive "double tsunami," scientists say. Waves created when a
magnitude-9.0 earthquake struck off the coast came together to create a
"merging tsunami" captured by satellites for the first time, according
to NASAa and researchers at Ohio State University. Peaks and troughs on
the ocean floor helped channel the waves into one huge wave, amplifying
its destructive force, they said. The tsunami swept across a long
stretch of coastline, swallowing up entire towns and villages, and
leaving almost 20,000 people dead or missing. NASA said two of its
satellites and a European satellite all happened to be passing over the
tsunami on the day of the disaster. They were equipped with instruments
capable of measuring changes in sea levels to an accuracy of a few
centimeters. Scientists said it was “a one in 10 million chance” they
were a able to observe the double wave with satellites.
