Earthquakes unlikely in the U.P.

HOUGHTON — From the devastation in Nepal to the minor shakes felt in the Lower Peninsula at the beginning of the month, earthquakes have been making headlines. It may make you wonder what the chances of a quake in the U.P. might be.

Wayne Pennington, Dean of the College of Engineering at MTU, holds a PhD in Geophysics and Geology, and he says that significant earthquakes in the U.P. are extremely unlikely. The Menominee area did experience a minor quake a few years back, but most seismic disturbances — about two or three in the last twenty years — have been brought on by the old underground mines in the area.

“Some mine collapses that technically could be considered earthquakes — that might occur,” said Pennington, “and those have occurred in recent years near some of the old abandoned mines, but otherwise, an earthquake say of magnitude two or greater or three or greater, where you start to feel them, [is] very unlikely.”

Pennington said the stable continental interior structure of the peninsula lowers the likelihood of large earthquakes.
Long ago, however, the area was much more active. Some features of those ancient days can still be seen.

“The Keweenaw Fault runs right through here, and a lot of people get concerned about that because it’s a major feature, goes a long way, separates rocks of very different types. In fact, if you go to Hungarian Falls, you can see essentially black rocks on one side and red rocks on the other side, and the fault is in between,” Pennington said. “It’s a very dramatic feature as faults go, but it hasn’t been active for about one billion years. That’s ‘b’ — billion.”

In the end, it looks like the ground in U.P. hasn’t been doing any significant moving and shaking in a very long time.