What types of sinkholes are there?
Collapse sinkholes form when surface materials suddenly sink into an underground cave or cavity. The cave/cavity forms slowly over time as groundwater moves along cracks in the water soluble bedrock and enlarges them. This type of sinkhole forms with little warning and leaves behind a deep, steeply sided hole. The actual collapse can happen in two different ways: 1. When a cavity gets very large, the roof becomes too thin to support the weight of any overlying rock or sediment, so it collapses into the cavity. 2. Sometimes caves are able to support the weight of the sediments above due to being filled with groundwater. But when groundwater levels are lowered, then the overlying sediment will first erode then collapse into the cavity. Caves and/or cavities begin to form underground; there is no evidence of ground subsidence Erosion process begins Cavities continue to grow larger; the roof of cavern becomes thinner and weaker, allowing more water to flow down into the rocks Diagrams cour
