North Dakota is not typically associated with seismic activity, but the state does experience earthquakes. It is situated in one of the most geologically stable areas of the North American continent, meaning earthquakes are extremely rare. When they occur, these events are generally minor, registering low on the magnitude scale, and are often imperceptible to the general population. The state’s low seismic profile is a direct result of its deep-earth geology, though modern resource development introduces a smaller possibility for human-caused tremors.
Historical Seismic Activity in North Dakota
North Dakota holds a position among the states with the fewest recorded earthquakes in the United States. Since the early 1900s, only about 13 earthquakes have been confirmed to originate within the state’s borders, occurring roughly once per decade.
The typical magnitude for these natural events is low, generally measuring 3.0 or less, which is often too weak to be felt by people. The largest event instrumentally recorded was the Magnitude 4.4 Huff earthquake in 1968, which was felt over a 3,000-square-mile area near Bismarck. Today, most small tremors are only detected by sensitive seismological monitoring instruments.
Prior to modern seismic networks, reports relied on personal accounts of ground shaking or rattled windows. Some historical activity has been noted in the eastern part of the state near the Red River Valley, as well as the Williston area in the west.
Geological Stability and Tectonic Context
The fundamental reason for North Dakota’s seismic quietude is its location far from active tectonic plate boundaries. The state lies deep within the North American Plate, insulated from the intense stresses and friction that cause large earthquakes at plate edges, such as the San Andreas Fault. North Dakota is underlain by the North American Craton, a core of ancient, stable crystalline rock formed billions of years ago.
This continental interior features a deep basement rock structure, with the Superior Craton underlying the east and the Wyoming Craton in the southwest. Any natural earthquakes that occur are classified as intraplate seismicity, meaning they happen within the interior of a tectonic plate. These tremors are caused by regional stresses transmitted from distant plate boundaries interacting with deep, pre-existing fault lines in the ancient basement rock.
Geologists speculate that deep-seated, buried faults, such as the Tabbernor Fault or the Thompson Boundary Fault, may be responsible for the rare, small quakes. These structures are remnants of ancient continental collisions and remain zones of weakness within the stable Craton.
Understanding Induced Seismicity
While natural earthquakes are rare, a separate modern concern involves induced seismicity, caused by human activity, particularly oil and gas development. This phenomenon is distinct from natural intraplate activity and is linked to the disposal of wastewater deep underground. The process involves injecting large volumes of produced water—a byproduct of extraction—into deep Class II disposal wells.
The fluid pressure from this injection can migrate and increase the pore pressure within the rock, potentially lubricating pre-existing faults. If a fault is already stressed by natural tectonic forces, the added fluid pressure can overcome the friction holding the fault in place, triggering an earthquake. This mechanism has caused significant increases in seismicity in other oil-producing states like Oklahoma and Texas.
North Dakota’s geology in the Williston Basin, home to the Bakken formation, appears to offer natural protection. Despite being a major oil-producing area with high-volume injection wells, the state has experienced little to no induced seismicity. This is partly because hydraulic fracturing stimulates rock layers only halfway down the geological column, generally avoiding the deeper, more tectonically stressed Precambrian basement rocks.
The combination of the Bakken’s unique geology and the fact that most oil and gas stimulation avoids the deepest fault structures has kept North Dakota’s seismic activity low. This is a contrast to regions where wastewater is injected directly into or near the ancient basement rock, which is more prone to induced tremors.