1867 Manhattan, Kansas earthquake
The Nemaha Ridge is about 50 miles east of the Midcontinent rift, a layer of basaltic rock that's very old, around 1.1 billion years. This rift (tear) stretches from Lake Superior in the north to Kansas in the south. In Kansas, the Central Kansas Uplift, with has faults, caused some small earthquakes in the late 1980s. According to Don Steeples, a geophysicist from the United States Geological Survey, earthquake activity has decreased in the Humboldt Zone but increased in the Uplift region.