Wednesday, September 26, 2012

Risk: The Quadra Quake--"Largest quake of its kind ever recorded"

From Earth Times:

Largest quake of its kind ever recorded
This map of the Indian Ocean region shows boundaries of Earth's tectonic plates in the area, and the epicenters (red stars) of two great earthquakes that happened April 11, 2012; Credit: © Keith Koper, University of Utah Seismograph Stations

Possibly the largest earthquake of its kind has been recorded in the Indian Ocean, say seismologists.
At least four faults in the Indo-Australian plate caused a magnitude-8.7 earthquake in April last year, say experts from the University of Utah and University of California, Santa Cruz.

The quake was previously believed to be of 8.6 magnitude, 40% smaller than the latest estimate, the scientists have reported in the Nature journal.

It happened when at least four undersea fault ruptured southwest of Sumatra, Indonesia, in less than three minutes. At least 10 people died from the quake or resulting heart attacks. The effects were felt from India to Australia, including South and Southeast Asia.

Taken as separate quakes, the magnitude of the ruptures would have been 8.5, 7.9, 8.3 and 7.8 on the "moment magnitude" scale that calculates the largest quakes, the seismologists say....MORE