BBC science news on Christchurch quake

by Yi Zhang

Here is a very interesting report on Christchurch quake happened last month, addressing the two major causes that have contributed to the damage in the city. The technique used in the mapping of the earth movement, called “synthetic aperture radar inteferogram”, gives a very precise (cm scale)  movements mapping of the landscape around the city. The damage was largely due to closeness of epicenter, located at the southeast suburb.  Another cause was the geostructure, in particular the liquifaction, the effect of which is demonstrated in the picture below (from the same report).