Ask the expert: Could Iowa have an earthquake?

Ask the expert
Could Iowa have an earthquake? Here’s what William Harmon Norton Professor of Geology Rhawn Denniston has to say:

Our part of the world generally experiences very few natural earthquakes. Fracking has changed the quake activity and risk a lot in recent years, largely in big producing states like Oklahoma, and even there, studies suggest that most of the bigger quakes are linked to a relatively small number of injection wells.

Iowa remains relatively immune to big quakes, though small ones are measured pretty regularly. The state does have deep fault lines—associated with an ancient, failed continental rift—that cross the state and could be tied to earthquakes (see the red arc in the center of the state on the chart).

The last really big Midwestern quake was 200 years ago in southeast Missouri. It is supposed to have been felt on the Eastern seaboard. If we got another one of those, Cornellians would certainly know it. However, studies of sediments in that area (the so-called Reelfoot Rift Zone) suggest that really big quakes like that one are exceedingly rare.