In a piece published today in The New Yorker titled Weather Underground: The Arrival of Man-Made Earthquakes, Rivka Galchen writes:
“Until 2008, Oklahoma experienced an
average of one to two earthquakes of 3.0 magnitude or greater each year.
(Magnitude-3.0 earthquakes tend to be felt, while smaller earthquakes may be
noticed only by scientific equipment or by people close to the epicenter.) In
2009, there were twenty. The next year, there were forty-two. In 2014, there
were five hundred and eighty-five, nearly triple the rate of California.
Including smaller earthquakes in the count, there were more than five thousand.
This year, there has been an average of two earthquakes a day of magnitude 3.0
or greater.
average of one to two earthquakes of 3.0 magnitude or greater each year.
(Magnitude-3.0 earthquakes tend to be felt, while smaller earthquakes may be
noticed only by scientific equipment or by people close to the epicenter.) In
2009, there were twenty. The next year, there were forty-two. In 2014, there
were five hundred and eighty-five, nearly triple the rate of California.
Including smaller earthquakes in the count, there were more than five thousand.
This year, there has been an average of two earthquakes a day of magnitude 3.0
or greater.
“William Ellsworth, a research geologist at the United States
Geological Survey, told me, “We can say with virtual certainty that the
increased seismicity in Oklahoma has to do with recent changes in the way that
oil and gas are being produced.” Many of the larger earthquakes are caused by
disposal wells, where the billions of barrels of brackish water brought up by
drilling for oil and gas are pumped back into the ground. (Hydraulic fracturing,
or fracking—in which chemically treated water is injected into the earth to
fracture rocks in order to access oil and gas reserves—causes smaller
earthquakes, almost always less than 3.0.) Disposal wells trigger earthquakes
when they are dug too deep, near or into basement rock, or when the wells
impinge on a fault line. Ellsworth said, “Scientifically, it’s really quite
clear.”
Geological Survey, told me, “We can say with virtual certainty that the
increased seismicity in Oklahoma has to do with recent changes in the way that
oil and gas are being produced.” Many of the larger earthquakes are caused by
disposal wells, where the billions of barrels of brackish water brought up by
drilling for oil and gas are pumped back into the ground. (Hydraulic fracturing,
or fracking—in which chemically treated water is injected into the earth to
fracture rocks in order to access oil and gas reserves—causes smaller
earthquakes, almost always less than 3.0.) Disposal wells trigger earthquakes
when they are dug too deep, near or into basement rock, or when the wells
impinge on a fault line. Ellsworth said, “Scientifically, it’s really quite
clear.”
