While South Dakota is not typically associated with seismic activity, history reveals that the state has experienced earthquakes. From the earliest recorded tremors in 1895 felt in the eastern Black Hills to more recent events, these occurrences provide a fascinating glimpse into the geological dynamics of the region.
According to data from the United States Geological Survey (USGS), here are the top five earthquakes that have left their mark on South Dakota:
Magnitude 4.2: Pierre’s New Year's Eve Shocker (1961)
On New Year's Eve in 1961, a magnitude 4.2 earthquake rattled Pierre and Fort Pierre residents at around 10:36 a.m. The epicenter was approximately 18 miles southwest of the capital city. The event caused widespread concern, with switchboards inundated by calls from people fearing an explosion. Flecks of plaster were discovered on furniture in the South Dakota Capitol Rotunda, highlighting the quake's intensity.
Magnitude 4.3: A Three-Time Visitor (1934, 1982, 2002)
Occurrences of a magnitude 4.3 earthquake have been documented three times in South Dakota's history. In July 1934, residents of Chadron, Nebraska, were awakened by shaking that reached as far as the Black Hills. Another instance occurred on November 3, 2002, near Butte, Nebraska, affecting southeastern South Dakota and extending to Sioux City, Iowa. Reports of cracked basement walls in several Nebraska towns underscored the quake's impact. A tremor near Tyndall, South Dakota, on November 15, 1982, marked the second of three such events within eight months.
Magnitude 4.4: Fort Thompson's Quake (1983)
On March 4, 1983, a magnitude 4.4 earthquake was recorded north of Fort Thompson, causing cracks in plaster walls and one concrete foundation. The tremors reverberated as far as Pierre and Sioux Falls. This event was the final of three earthquakes recorded within eight months.
Magnitude 4.5: Alpena's Tremor (1911)
On June 2, 1911, a magnitude 4.5 earthquake centered near Alpena sent shockwaves across towns within a hundred-mile radius. Reports from Huron described rattling dishes and broken glass fronts in stores, prompting residents to flee their homes and seek refuge in the streets.
Magnitude 5.1: Southwest South Dakota Shakes (1964)
Southwestern South Dakota experienced significant tremors on March 28, 1964, from an earthquake registering 5.1 on the Richter scale. Centered near Merriman, Nebraska, the quake caused cracks in roadways, collapsed riverbanks, falling plaster, and damage to goods in homes and stores. Just a day before, the most powerful earthquake in US history, a magnitude 9.2, rocked southern parts of Alaska.
