2011-2-24

NZ earthquake illustrates risks for U.S. west coast

The recent 6.3 magnitude earthquake in Christchurch, New Zealand, killed many more people and caused far more damage than the September 2010 7.1 magnitude earthquake which struck the same area; the reason: even though this earthquake was weaker than last year's event, it was much shallower; was situated directly under Christchurch; hit during the lunch hour when more people were exposed to damage; and shook sediments that were prone to "liquefaction," which can magnify the damage done by the ground shaking; scientists say the same description nicely fits many major cities and towns in Washington, Oregon, California, and British Columbia.