More Earthquakes This Year? Scientists Say 'No'
Rescue workers search for survivors at the site of a collapsed building in Yushu county in western China's Qinghai province on Wednesday, April 14, 2010. A series of strong earthquakes struck a far western Tibetan area of China on Wednesday, killing at least 400 people and injuring more than 10,000 as houses made of mud and wood collapsed, trapping many more, officials said. (AP Photo)
Los Angeles has been all a-twitter about the apparent increase in the number of major earthquakes locally as well as globally this year. But is it true? Has 2010 actually seen an increase in earthquake frequency, compared with previous years?
The Los Angeles Times ran a graphic several days ago showing a dramatic increase in earthquakes magnitude 4.0 and greater, at least for Southern California, suggesting we've seen two and a half times more earthquakes in 2010 compared with recent years. But even if there has been a local increase in small and moderate quakes, what about global data? Recent major earthquakes in China, Haiti, Chile, and Mexico have engendered lots of speculation.
A recent report from the US Geological Survey says:
Scientists say 2010 is not showing signs of unusually high earthquake activity. Since 1900, an average of 16 magnitude 7 or greater earthquakes — the size that seismologists define as major — have occurred worldwide each year. Some years have had as few as 6, as in 1986 and 1989, while 1943 had 32, with considerable variability from year to year.
This suggests that the six major earthquakes that have occurred in the first four months of 2010 puts us well within the normal range. Though the recent earthquakes have not been unusual, they are a reminder of the destructive power of earthquakes when they occur in densely populated areas — especially areas in which the buildings are not designed to withstand earthquakes. This is a good reminder for us to do everything we can to be sure our homes, businesses, and schools are well-prepared.