By Summit Voice
SUMMIT COUNTY — Federal scientists with the U.S. Geological Survey say they’ve detected a “remarkable” increase in the rate of earthquakes in the middle of the country, most likely related to oil and gas drilling activities.
All in all, the average number of quakes magnitude 3 or greater has increased six-fold since 2001 over 20th century levels. None of the quakes have caused injuries or property damage.
“While the seismicity rate changes described here are almost certainly manmade, it remains to be determined how they are related to either changes in extraction methodologies or the rate of oil and gas production,” USGS researchers wrote in an abstract of a recent paper.
Between 1970 and 2000, the average number of earthquakes stronger than magnitude 3 was at about 21, plus or minus seven. That rate increased to about 29 per year (plus or minus three) between 2001 and 2008, and jumped to 50 in 2009, 87 in 2010 and 134 in 2011.
“A naturally-occurring rate change of this magnitude is unprecedented outside of volcanic settings or in the absence of a main shock, of which there were neither in this region,” the researchers wrote.
Researchers have pointed out that no earthquake triggered by fluid injection has ever caused serious injury or significant damage, although that may not be quite enough to soothe some residents who feel beset by energy development in their neighborhoods.
Scientists have known for several decades that quakes can be triggered by injection of fluids deep into the ground. Some of the first well-documented cases were earthquakes around Rocky Mountain Arsenal.