A sinkhole opened up below this street, causing the pavement to crack and cave in. This sinkhole is very small. Some sinkholes are larger, much larger.
Amazing but True!
- Sinkholes generally form where underlying limestone rock dissolves in ground water. The rock becomes weaker and eventually caves in. Any soil, pavement, or structures overlying the rock may cave in as well.
- In some parts of the world, sinkholes are very common because of the geology. For example, sinkholes are found all over the state of Florida. They are a natural part of the landscape of the state.
- In 1981, a gigantic sinkhole opened up in the middle of the city of Winter Park, Florida. Take a trip back in time to the formation of the Winter Park sinkhole by watching the following video. It contains TV news clips from 1981 and also shows what the sinkhole looked like 27 years later in 2008.
What Do You Think?
At the links below, learn about the science behind sinkholes. Then answer the questions that follow.
- Ground water is somewhat acidic. Why is ground water acidic? How do you think the acidity of ground water affects the rate at which it can dissolve limestone?
- Limestone typically dissolves faster in areas where precipitation is higher. Why do you think this is the case?
- Acid rain falls in some parts of the world. This is rain that is more acidic than normal rain because of pollution in the air. How do you think acid rain might affect the rate at which limestone dissolves?
- Sinkholes are more likely to form where the rate of limestone dissolving in ground water is higher. What factors do you think might increase the risk of sinkholes forming in an area?
- Why do you think many sinkholes become ponds or lakes?