What is a sinkhole?

Sinkholes typically form in landscapes where the bedrock is soluble, such as limestone, gypsum, or salt. Slightly acidic groundwater gradually dissolves the rock underground, creating hidden cavities and voids. When the roof of such a cavity can no longer support the weight of the soil and rock above, the surface collapses into the empty space, producing a sinkhole. Some develop slowly as gentle depressions, while others, called cover-collapse sinkholes, can open up abruptly and swallow roads, cars, or buildings. Human activity, like heavy groundwater pumping or leaking pipes, can accelerate their formation. Regions rich in soluble rock, known as karst terrain, are especially prone to sinkholes.