Image via WikipediaJanuary 10, 2011 - SUMATRA, INDONESIA - An early morning earthquake measuring Magnitude 7.3 struck Sumatra at 1:36 AM (Jakarta time; Tuesday, January 10, 2012 at 6:37 PM UTC), prompting a tsunami warning for Indonesia. The tsunami warning has since been cancelled.
The M7.3 quake's epicenter was off the northern coast of the Indonesian island of Sumatra, about 423 km (262 miles) southwest of Banda Aceh, Sumatra, Indonesia. The quake was centered 29.1 km (18.1 miles) beneath the ocean floor. The coordinates of the epicenter: 2.396°N, 93.175°E.
The U.S. Geological Survery (USGS) reported that the earthquake off the west coast of northern Sumatra, Indonesia, "occurred as a result of strike-slip faulting within the oceanic lithosphere of the Indo-Australia plate, approximately 100 km to the southwest of the major subduction zone that defines the plate boundary between the Indo-Australia and Sunda plates offshore Sumatra. At the location of this earthquake, the Indo-Australia plate moves north-northeast with respect to the Sunda plate at a velocity of approximately 52 mm/yr. While rare, large strike-slip earthquakes are not unprecedented in this region of the Indo-Australian plate. Since the massive M 9.1 earthquake that ruptured a 1300 km long segment of the Sumatran megathrust plate boundary in December of 2004, two Mw 6.2 strike-slip events have occurred within 50 km of the January 10 2012 event, on April 19 2006, and October 4 2007. These events seem to align with fabric of the sea floor in the diffuse boundary zone between the Indian and Australian plates." More info at USGS site.
Yesterday, we noted the M5.1 quake that hit off the northern coast of Papua, Indonesia.
