How fracking caused 109 earthquakes in Ohio town

Caption: Anti-fracking protestors demonstrate at the state legislature in Albany, New York, in this photo. The recent surge in U.S. oil and gas production has been linked to an increase in small to moderate induced earthquakes in Oklahoma, Arkansas, Ohio, Texas and Colorado. (Reuters photo.)

For over a century, there were no earthquakes in Youngstown, Ohio. In fact, there were no recorded seismic events in the town since observations began in 1776. But between December 2010 and December 2011, Youngstown recorded 109 earthquakes.

So what gives?

Fracking. So say authors of research published in the journal Geophysical Research Letters.

Fracking involves injecting millions of litres of water and thousands of litres of chemicals underground at very high pressure to create fractures in shale rock formations to extract previously inaccessible natural gas. An average well takes four million to eight million gallons of water to drill in and frack. There can be up to 20 wells on a single pad that is spread over an acre.

It is considered a boon because it has opened a hidden treasure trove; it has also divided communities, created fears about health.

In December 2010, Northstar 1, a well built to pump wastewater produced by fracking in the neighbouring state of Pennsylvania, came online. In the next 12 months, Youngstown recorded 109 earthquakes; the strongest was a magnitude 3.9 quake on Dec. 31, 2011.

The authors of the study analyzed the earthquakes and found that their onset, cessation, and temporary dips were tied to activities at the Northstar 1 well. The first earthquake recorded in the city occurred 13 days after pumping began; the tremors stopped soon after the Ohio Department of Natural Resources shut down the well in December 2011.

Won-Young Kim, a seismologist at Columbia University and one of the authors of the study, said the earthquakes in Youngstown were directly caused by the pressure buildup and stopped when pressure dropped.

The earthquakes, according to the paper, were apparently centered in an ancient fault near the Northstar 1 well, and pressure from wastewater injection caused this fault to rupture.

However, of the 177 wastewater disposal wells of this size active in Ohio during 2011, only the Northstar 1 well was linked with this kind of seismic activity, suggesting this ability to cause earthquakes was rare. 

Repost of blog article by:  Raveena Aulakh, How fracking caused 109 earthquakes in Ohio town