WASHINGTON (AP) — A new study explains how just four wells forcing massive amounts of drilling wastewater into the ground are probably shaking up Oklahoma.
A Cornell University study published Thursday in the journal Science shows those wells seem to have triggered more than 100 small-to-medium earthquakes in the past five years. Many of the quakes were much farther away from the wells than expected.
The study found that those wells, combined, pour more than 5 million gallons of water daily a mile or two underground into rock formations. The study's lead author, Cornell University seismologist Katie Keranen, says that buildup of fluid creates more pressure that "has to go somewhere."
Researchers originally figured the water diffused through underground rocks slowly, but Keranen says instead it's moving faster and farther and triggers quake fault lines that already were likely ready to move. She adds that not much added pressure is needed to trigger the fault lines.
The study shows the likely way in which the pressure can trigger fault lines, which already existed yet were not too active. Keranen says, however, that researchers need more detail on the liquid injections themselves to absolutely prove the case.
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