© Earth Observatory / NASANASA Earth Observatory image by Robert Simmon, using ALI data from the EO-1 Team and USGS Earthquake Hazard Program. Acquired March 4, 2011.
It is a modern human tendency to focus on the number of an earthquake - specifically, the magnitude, or what people used to call the "Richter scale." But the destruction from a quake usually has more to do with location and timing. Such was the case with the earthquake in Christchurch, New Zealand, on February 22, 2011.
A September 2010 earthquake centered 40 kilometers (25 miles) west of Christchurch, in the plains near Darfield, struck at 4:35 a.m., had a magnitude of 7.1, and caused some structural damage and one death (by heart attack). The earthquake in February 2011 occurred at 12:51 p.m. and just 10 kilometers (6 miles) from the center of Christchurch. It had a magnitude of 6.3, though was officially classified - scientifically speaking - as an aftershock of the 2010 quake. At least 166 people died, and the city of Christchurch was devastated structurally and emotionally. Many people are still missing.
The natural-color image above was captured on March 4, 2011, by the
Advanced Land Imager (ALI) on NASA's
Earth Observing-1 (EO-1) satellite. Overlain on the map are seismological measurements of the ground shaking in the Christchurch area on February 22, as noted by the U.S. Geological Survey's Earthquake Hazard Program.