For those who want a more detailed explanation of the massive Sumatran earthquake than you’ll get from CNN, the BBC, or the NYT, check out the US Geological Survey page for the quake. Not only was it a huge quake; it was the result of a huge shift: “Preliminary locations of larger aftershocks following today’s earthquake show that approximately 1000 km of the plate boundary slipped as a result of the earthquake.” The accompanying map shows the location of the plates and faults; the Indian plate is moving northwards into the Burma plate at 6 cm a year.
I couldn’t find much on the web about seismic activity in this area. Roger Bilham’s history of earthquakes in India is a reasonable starting point. If readers know of other good studies, could you link to them in comments to this blog entry? And please consider making a donation to the Red Cross, or the emergency aid organisation of your choice.