Earthquakes, landslides, sinkholes, soil liquefaction, rockfalls and even mine collapse occur in Missouri
A geologic hazard is one of several types of geologic events that can put lives and property in danger. In Missouri, geologic hazards consist of a wide range of phenomena and include: earthquakes, landslides, sinkholes, soil liquefaction, rockfalls and even mine collapse.
Most Missourians are familiar with the large 1811-1812 earthquakes that occurred in the New Madrid Seismic Zone (NMSZ) in southeast Missouri. However, Missouri experiences small earthquakes nearly every day. These earthquakes typically are too small to be felt but are recorded on seismographs, devices that measure the earth’s movement. While these earthquakes are more frequent in the NMSZ in southeast Missouri, they also occur on other faults located in Missouri and surrounding states.
Sinkholes are depressed or collapsed areas formed by dissolution of carbonate bedrock or collapse of underlying caves. Much of Missouri, especially the Ozarks, is underlain by bedrock susceptible to sinkhole development. Sinkholes are part of what is called “karst” topography and also includes caves, springs and losing streams. Aside from structurally impacting foundations of homes and other buildings, sinkholes often serve as direct conduits for rapid surface water infiltration into the underlying groundwater aquifer. Contaminants near or at the surface can quickly enter the aquifer and pollute drinking water supplies.
Landslides, slumps and rockfalls are potential geologic hazards throughout Missouri. They often can be triggered when surficial materials are disturbed or modified by man. Rockfalls are common hazards in areas that have bluffs or extremely steep hillsides. Landslides and rockfalls can vary in size from small to very large. In general, the higher and steeper the slope, the farther and faster the landslide or rockfall will travel.
Although man-made, collapsing mines also pose a geologic hazard. Abandoned mines occur throughout Missouri and include both surface pits and underground workings. Old mines were typically abandoned without proper reclamation or closure. These pits and underground voids can pose a public safety hazard.
Learn more about geologic hazards in Missouri.