What can cause a sinkhole to form?
Rainfall absorbs carbon dioxide and reacts with decaying vegetation, creating slightly acidic water. When this water reaches the limestone aquifer, it moves through spaces and cracks slowly dissolving the limestone and creating a network of cavities and voids. As the limestone dissolves, pores and cracks are enlarged and carry even more acidic water. Water not only contributes to the chemical dissolving of the limestone but it also affects the support or lack of support provided to a cavity when the water level changes. A sinkhole is formed when the land surface above a cavity collapses or sinks into the cavity or when surface materials are carried downward into the voids. A natural drought or the pumping too much groundwater can leave underground cavities empty. This can make conditions favorable for sinkholes to form. Also, heavy rains following a drought often cause enough pressure on the ground to create sinkholes. Sinkholes can be triggered by human activities such as: • Over pump
