Keywords: Christchurch from space, 4 March 2011, showing quake shaking strength, with key.png en Satellite image of Christchurch and surrounding areas on 4 March 2011 about two weeks after the 2011 Christchurch earthquake Circle colour indicates shaking strength with deeper red meaning stronger shaking as shown in the key under the image <br/> NASA's caption 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 <br/> 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 <br/> 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 not in this high resolution version 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 The deeper the red color of the circle the more intense the peak ground acceleration or shaking of the earth Note how intensity is highest right around the most densely developed areas of Christchurch City officials and news accounts also described liquefaction ”the softening and loosening of the soil due to shaking and groundwater penetration ”that was 300 to 500 percent worse than during the September 2010 earthquake <br/> There are two forms of energy that cause the shaking in an earthquake P or primary waves provide the initial often vertical jolt that lifts people and structures off the ground S or secondary waves lead to horizontal shaking Most structures collapse during the longer-duration S waves because buildings are not designed to handle this side-to-side motion In Christchurch the quake occurred so close by that the lag between P and S waves was a mere second Christchurch_from_space _4_March_2011 _showing_quake_shaking_strength jpg and shaking strength palette from the same NASA webpage 2011-03-09 21 49 UTC Christchurch_from_space _4_March_2011 _showing_quake_shaking_strength jpg NASA Earth Observatory image by Robert Simmon using ALI data from the EO-1 Team and USGS Earthquake Hazard Program Caption by Mike Carlowicz derivative work combining with key/palette Avenue <span class signature-talk >talk</span> <gallery> File Christchurch and surrounding area from space 4 March 2011 jpg Higher resolution wider view without annotations </gallery> PD-USGov-NASA If I have any legal rights over this combined image I release it into the public domain --Avenue <span class signature-talk >talk</span> 22 42 9 March 2011 UTC Original upload log This image is a derivative work of the following images File Christchurch_from_space _4_March_2011 _showing_quake_shaking_strength jpg licensed with PD-USGov-NASA 2011-03-09T12 28 41Z Avenue 720x480 177766 Bytes <nowiki> en Satellite image of Christchurch and surrounding areas on 4 March 2011 about two weeks after the 2011 Christchurch earthquake NASA's caption It is a modern human tendency to focus on </nowiki> Uploaded with derivativeFX 2011 Canterbury earthquake Satellite pictures of New Zealand NASA Earth Observing-1 images |