This interview originally aired on "In the Moment" on SDPB Radio.
South Dakota gets a few earthquakes a year, and one such quake struck near Wakonda on Sunday night. Like most South Dakota earthquakes, it was a small one.
Tim Cowman, state geologist at the South Dakota Geological Survey, discusses why this area is prone to less intense earthquakes and what causes them.
Hint: One cause has to do with the most recent ice age.