A United States Geological Survey (USGS) document released last week documents an increase in earthquakes likely caused by human activity, mapping 17 seismically active pockets in eight states.
The USGS map:
While the document does not state the causes of the quakes, it points out that there has been a “substantial increase” in quake rates since 2009, and that the increase is attributed by other studies to the “injection of wastewater or other fluids in deep disposal wells.”
The rise in these earthquakes since 2009 directly coincides with the fracking boom in these areas:
“This new report describes for the first time how injection-induced earthquakes can be incorporated into U.S. seismic hazard maps,” said Mark Petersen, Chief of the USGS National Seismic Hazard Modeling Project. “These earthquakes are occurring at a higher rate than ever before and pose a much greater risk to people living nearby.”
After years of officially ignoring the link between fracking and earthquakes, the state’s science and energy cabinet admitted last week that “it (is) very likely that the majority of recent earthquakes, particularly those in central and north-central Oklahoma, are triggered by the injection of produced water in disposal wells.”
What does it mean for the Yellowstone caldera?
While Montana and North Dakota have not seen this same level of induced earthquakes, the juxtaposition of the USGS report with a new report, also issued last week, by a team of University of Utah scientists on seismicity in the Yellowstone volcanic system offers a reminder that what we don’t know about earthquakes and fracking should scare us.
The report describes for the first time a large reservoir of hot rock, mostly solid but with some melted rock in the mix, that lies beneath a shallow, already-documented magma chamber. The newly discovered reservoir is 4.5 times larger than the chamber above it. There’s enough magma there to fill the Grand Canyon. The reservoir is on top of a long plume of magma that emerges from deep within the Earth’s mantle.
While the report doesn’t change the timetable for a future major eruption, it is a reminder that we act at great risk if we jostle the earth’s crust. The report indicates that the next earthquake in the region could occur within the boundaries of Yellowstone Park, just 60 miles away from drilling activity in Stillwater and Carbon County.