Monday, March 6, 2017

MAPS: Last 30 days of Oklahoma earthquakes

Rather remarkably, though, the USGS conclude that, in 2017, "the forecasted chance of damaging ground shaking in central Oklahoma is similar to that of natural earthquakes in high-hazard areas of California", and that's nearly entirely down to fracking in the Middle America state. USGS also identified the Raton Basin, straddling Colorado and New Mexico, as a high-hazard area. On September 3, 2016, the largest recorded natural disaster in Oklahoma - a 5.8-magnitude quake in the town of Pawnee to the north - was felt as far south as Dallas. That might be due to regulatory actions or because gas and oil extraction and demand has fallen with the falling prices of petroleum.
In a statement, Mark Petersen of the USGS said the amount of injected wastewater in some areas has been reduced by up to 40% in 2016.
In the past, this entailed USGS scientists projecting potentially unsafe seismic activity well into the future, using time scales around a half-century, and only considering naturally-caused earthquakes. The new forecast maps show how our appetite for fossil fuels is changing America's seismic landscape, and how hard it will be to predict quakes in the future.
Much (but not all) of the wastewater injection is associated with the fracking boom, which has led the practice to become more common in recent years, especially in Oklahoma.
The contaminated water becomes too unsafe to dump anywhere, since it could seep into regular groundwater, so companies shoot the wastewater deep into the earth, between layers of hard rock.
The drop is the result of fewer earthquakes occurring in 2016 than in 2015, the USGS said. This results in the oil companies dealing with more wastewater than previously.
But the number of quakes is only part of the story.
But since 2008, certain parts of the United States have been rocked by swarms of earthquakes, the vast majority of which are caused by the practice of disposing oil and gas field wastewater deep underground.
That's the conclusion of a new report that cites wastewater disposal from fracking as triggering the quakes.
"The significantly decreased number of earthquakes in north Texas and Arkansas was not expected, and this was likely due to a decline in injection activity", the USGS add.
The New Madrid Seismic Zone (NMSZ), a source of quakes for several states in the southern and midwestern United States, has been listed as a high hazard zone.
The number of Americans affected this year is less than last year, when the the agency reported 7 million were at risk.
California remains the state with the greatest risk of natural earthquakes.
The environmental groups the Natural Resources Defense Council and the Sierra Club want all fracking stopped. The Sierra Club launched an earthquake-related ad urging senators to vote against Pruitt's confirmation.
Mr. Petersen chalked up the natural disaster decreases to "regulatory actions by state officials starting about 2014, when they restricted injections and closed some wells, but it's also potentially related to the declining price of oil, which reduced injected volumes of wastewater".
According to a Popular Science report, studies have definitively connected wastewater injection with a surge in human-induced natural disaster activity in a specific area.
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