Monday, April 09, 2012
Big increase in Arizona seismicity in 2011
In 2011, there were 131 earthquakes detected by instruments in Arizona. The largest events of the year were magnitude (Md) 3.7 and 3.6 near Clarkdale in central Arizona, according to a summary compiled by AZGS seismologist Lisa Linville, and published today in our online magazine, Arizona Geology.
In 2010, there were 53 earthquakes recorded. Overall, seismic activity in 2011 represents a 160% increase from 2010, a 100% increase from 2009, and a 31% increase from 2008. About 36% of the quakes in 2011 were associated with swarms of small magnitude events that occurred over the space of a few days.