We don't get a lot of earthquakes, but we can feel them farther away
Some people in Michigan could feel the earthquake that happened last week in Ontario.
It turns out, earthquakes east of the Rockies can be felt much farther away than earthquakes out West.
Oliver Boyd is a research geophysicist with the U.S. Geological Survey.
“In the eastern United States, the ground beneath us, the rocks tend to be much older. They’re also colder and denser, and then any fractures or faults that are present within the rock have had more time to heal. So seismic waves can travel much more efficiently in the east than they do in the west,” says Boyd.
Boyd says of course, we get fewer earthquakes east of the Rockies, and they're especially rare in Michigan.
"Since 1980, there have been three magnitude 3-plus earthquakes," says Boyd, "One in 1994 and two in 2015, and then the largest historic earthquake in the state was in 1947. So there haven't been very many earthquakes in Michigan, but Michigan can still feel earthquakes that occur outside of the state."
For example, he notes people in Michigan felt the 5.8 magnitude earthquake in 2011 that happened in Mineral, Virginia.
Boyd says older buildings in the East weren’t designed with earthquakes in mind, so sometimes there can also be more structural damage.