Saba Mahmood

What is a sinkhole?

A sinkhole is a cavity in the ground/ a natural depression in the Earths surface which is caused by water erosion. Sinkholes are caused by water that erodes certain types of rock. This erosion takes place under the ground and is similar to how caves are formed. Areas of limestone and salt beds are most at risk to this erosion.

What kind of bedrock is most likely to form sinkholes?

Carbonate rocks mostly form sinkholes. Sinkholes are common where the rock below the land surface is limestone, carbonate rock, salt beds, or rocks that can naturally be dissolved by ground water circulating through them. As the rock dissolves, spaces and caverns develop underground.

Where are they common?

Sinkholes are common in Florida, but rarely cause deaths.

In NC, they are common in the outer coastal plain. Most NC sinkholes are flooded

What are causes of sinkholes? (Human & Natural )

Human Causes:

In some cases, sinkholes appear because of the combination of industrial activity or development.

Some things that cause sinkholes are

  • Drilling and vibrations
  • Mining
  • Changes in weight
  • Lots of foot or vehicle traffic
  • Heavy increase in water flow, formation of a pond or body of water, or broken pipes, among other things

The Biggest Sinkhole

The biggest sinkhole, located in Cairo, Egypt, has a cavity of 440 feet below sea level at its lowest point, with a length of 186 miles and a width of 95 miles.