Comparable Rupture Area

Magnitude 9.0 OFF W COAST OF NORTHERN SUMATRA
Sunday, December 26, 2004 at 00:58:49 UTC

comparable rupture area of M9.0 earthquake
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Earthquakes rupture a patch along a fault's surface. Generally speaking, the larger the rupture patch, the larger the magnitude of the earthquake. Initial estimates based on the aftershock distribution show the magnitude 9.0 Sumatra-Andaman Islands Earthquake ruptured a patch of fault roughly the size of California, and modeling of the seismic waves show that most of the slip occurred in the southern 400 kilometers of the patch. For comparison, a magnitude 5 earthquake would rupture a patch roughly the size of New York City's Central Park.