Summary 14

Lovett R A. Past quakes cause future shocks. Nature [Internet]. 2009 Sept 30 [cited 2009 Sept 30]; doi:10.1038/news.2009.964. Available from: http://www.nature.com.mutex.gmu.edu/news/2009/090930/full/news.2009.964.html

After examining closely 22 years of data collected by seismologists, US seismologists have concluded that even distant earthquakes can lower the earthquake threshold and cause distant earthquakes. In late 2004 there was the Sumatra-Andaman earthquake. Following that larger earthquake, the San Andreas Fault had many smaller quakes. Scientists also saw an increase in what is believed to be underwater movements after larger earthquakes likely due to cracks and weak spots forming from the tension placed on the earth.
Scientists have also started studying at a station called the San Andreas Fault Observatory at Depth. There they have drilled a 3 km deep hole into the fault and placed detectors into the fault. This detector placed so deep can detect tiny earthquakes that would remain unknown on the surface. Hopefully, this will give more information that can let us know when to expect an earthquake to occur. Scientists also hope to find an answer to the enigma of why the New Madrid fault, which has had 2 major earthquakes in the past 2000 years, stays so quiet for so long, then has huge movements.