What is a sinkhole? What causes sinkholes?

What is a sinkhole? What is a sinkhole? This article will give you the answer.

Beneath the surface of the earth are different layers of soil and rock. When the surface of the earth is no longer supported by anything underneath, it will cause subsidence and create sinkholes. These holes are often very deep, capable of "swallowing" everything from people, vehicles to houses.

Sometimes, there may be a cavity forming under the ground surface that we are not aware of.

For example, over time, limestone can be dissolved by water. Where the limestone once occupied, it gradually opens up, creating a space that can become a spectacular cave when large enough. But if these cavities exist too close to the surface, the top layer of land can suddenly collapse, creating a sinkhole.

Sinkholes can happen anywhere.

The phenomenon of "death holes" is not uncommon in the world. It often occurs in areas with special geological structures such as soft ground; underground mines of stone, limestone or gypsum; or voids in the ground.

Erosion in the ground can take place over several years, but subsidence occurs very quickly and suddenly.

In addition to natural causes, sinkholes can also appear in other places and be created by human activities. For example, sinkholes can appear in places where many coal mines have been dug and abandoned, in places affected by construction and groundwater pumping.

When encountering a sinkhole in real life, people should stay away from its edges because the edges can widen the hole.

In summary, sinkholes are mainly caused by water:

1. Water dissolves minerals in rocks, leaving behind residue and voids within the rock. (This is called "weathering").
2. Water washes away soil and debris from the pores in the rock.
3. Lowering the water table can cause soft material in rock voids to lose their support, potentially leading to collapse.
4. Changing the groundwater gradient (by removing or introducing water into the system) can cause loose material to flow out of the pores more rapidly and the surface to collapse in response.
5. Any change to the hydrological system (adding water or removing water) causes the system to become at least temporarily unstable and can lead to a sinkhole.
6. Sinkholes can result from seasonal changes in groundwater levels, freezing and thawing of the ground, and extreme rainfall (drought vs. heavy rain).

Lesley Montoya

Update 29 May 2025