Human-caused earthquake rocks Chicago

On November 4, an earthquake shook the suburbs of Chicago. It was an incredibly rare event for the region, and now scientists say it was caused by human activity. Specifically, explosions in a quarry set off the quake — and could do it again.

According to Alex Ruppenthal, on My Suburban Life:

Scientists still think the blast and earthquake were related, considering the rarity of seismic events in the Chicago area.

"The working hypothesis is this shallow seismic event is somehow associated with the quarrying process and that it was somehow triggered by this very small explosion," said Jim Dewey, geophysicist at the USGS' National Earthquake information Center in Colorado. "It's very likely [the events were connected] just because it would be such an extraordinary coincidence otherwise."

[Dewey] estimates it will take several years to figure out what exactly happened, in addition to what should be done about it . . . he could think of only five or six cases since the mid-1970s in the world where quarry activity was linked to an earthquake.

"We're sort of in the awkward position of being in effect a doctor diagnosing some weird illness that we don't really know how best to treat," he said.

The USGS is considering installing its own seismographs at the quarry to help determine whether "micro earthquakes" are occurring there regularly, Dewey said. If so, seismographs would allow scientists to locate the quakes' origins to within 30 meters, information that could allow quarry operators to adjust operations to prevent triggering shocks, Dewey said.

This certainly wouldn't be the first human-caused earthquake, but it's a good indicator that mining operations may damage the environment in unexpected ways — such as by shaking suburbs that are miles away.

Read more via My Suburban Life