Earthquakes

We have had some grim reminders recently of the power of earthquakes and the tragic consequences that can result from them. Here in the northern Great Plains we may have to deal with other natural disasters such as tornados, but thank goodness we do not live in an area prone to earthquakes.
The earth’s crust is composed of a dozen or so variously sized tectonic plates which float on the underlying material and move at the rate of a few inches per decade. Most earthquakes occur at plate boundaries. A good example is the west coast of North America where the Pacific Plate is subducting under the North America Plate. As with other boundaries, the area is often characterized by earthquakes and perhaps volcanic activity.
Because we live about as far away as you can get from a plate boundary, earthquakes are of little concern. The same is true for our neighboring states and provinces with the exception of Montana. As most everyone knows, parts of Montana are quite geologically active. Just think Yellowstone National Park.
However, there have been a few measurable earthquakes in our state. I took a quick look at former state geologist John Bluemle’s “The Face of North Dakota” for information on North Dakota earthquakes.
It might surprise you, but Bluemle discusses two faults that may underlie North Dakota. If present, they are deep and not very active, so would be of little concern. However, an illustration shows both faults trending north-south with one, the Tabbernor Fault passing just to the east of Hebron while the Thompson Boundary Fault similarly passes near Huff.
The Thompson Boundary Fault may have been a factor in one of our more recent earthquakes. I suppose there are a few among us that can recall the earthquake from the summer of 1968 that occurred near Huff, located on the west side of the Missouri River south of Mandan. It rattled the dishes, registering 4.4 on the Richter Scale.
If you would like to learn more about North Dakota earthquakes, I have put a link to an interesting article about them from the North Dakota Geological Survey’s website along with the text of this Natural North Dakota. You can access it at prairiepublic.org. You might also want to peruse the North Dakota Geological Survey’s website for other interesting geological information.

Here is the link to “Earthquakes in North Dakota?” by John Bluemle, North Dakota Geological Survey.
Chuck Lura

Natural North Dakota is supported by NDSU Central Grasslands Research Extension Center and Minot State University-Bottineau, and by the members of Prairie Public. Thanks to Sunny 101.9 in Bottineau for their recording services.