What causes sinkholes? It's a question that's been on many minds lately, following the news that a sinkhole had opened suddenly beneath a home not far from Tampa, Fla. last Thursday and swallowed up a man who lived there.
As the name suggests, sinkholes are naturally occurring holes in the surface of the earth. Sinkholes can form gradually or -- as in the tragic case in Florida -- suddenly. They form in areas where water flowing underground has dissolved rock -- typically limestone -- below the surface, leading to the formation of underground voids into which the surface sediment falls, according to the website of the Florida Sinkhole Research Institute. They vary in size from 1 to 600 meters.
Sinkholes are found all over the world. In the U.S., sinkholes are especially common in Texas, Alabama, Missouri, Kentucky, Tennessee, Pennsylvania, and Florida, according to the U.S. Geological Survey.