A man in Florida died after a sinkhole opened beneath his bedroom, swallowing him as he slept. A golfer broke his shoulder when a sinkhole opened on a golf course in Illinois. Suddenly it seems sinkholes are making news everywhere. But scientists insist they're a common and naturally occurring geologic phenomenon. Sinkholes usually occur on the fragile terrain called “karst," which underlies about 20 percent of the United States. Sinkholes also can be triggered by human activity. We learn what sinkholes reveal about the interconnectedness of life above and below ground, our freshwater supplies and climate change.
This simplified map shows the areas with potential for sinkholes and karst in the conterminous United States (Source: U.S. Geological Survey)