Throughout the world, the number of sinkholes are increasing from Florida (US) to Konya (Turkey). Sinkholes are threatening lives and swallowing up a huge amount of farmland. How they form and collapse look quite mysterious, but actually the science behind them is simple. Though, preventing them is challenging.
First of all, what is a sinkhole? Carbonic acid is formed as a result of the combination of groundwater with carbon dioxide. This carbonic acid dissolves the soils where the limestone is dense over time and causes the formation of caves underground, after a while the soil above the cave collapses. The deep pits formed as a result of this collapse are called sinkholes. They are basically huge holes above ground. They vary in size from 1 to 600m both in diameter and depth. They may form gradually or suddenly, and they are found all around the world. National Geographic explains the formation of sinkholes as follows: “In a landscape where limestone sits underneath the soil, water from rainfall collects in cracks in the stone. These cracks are called joints. Slowly, as the limestone dissolves and is carried away, the joints widen until the ground above them becomes unstable and collapses. The collapse often happens very suddenly and without very much warning. Water collects in these collapsed sections, forming sinkholes”.
Sinkholes may be formed by natural processes as well as artificial processes. Some sinkholes can be triggered by human activities such as over withdrawal of water, diverting surface water from a large area and concentrating it in a single point, artificially creating ponds of surface water, and drilling new water wells.
Suddenly appearing and swallowing up the ground, sinkholes are scary and hazardous. They can destroy buildings and highways.
However, some sinkholes are beneficial and mind blowing natural beauties. Here are some examples of sinkholes from National Geographic:
Yucatan Peninsula in Mexico:
These sinkholes are called “cenotes”. People are using cenotes due to their ability to collect natural water.
Chichen Itza, Mexico:
This sinkhole is also a cenote. It is a natural underground reservoir of rainwater and serves as the main source of freshwater in a region where water is scarce.
Naturally occurring sinkholes cannot be prevented, yet those created by human activity may be prevented. By keeping water tables high, water conservation rules and drought restrictions are tools to help prevent sinkholes from occurring. Generally, it can be difficult to know exactly where or when a sinkhole will strike, but getting geological surveys done and using penetrating radar (GPR) for sinkhole risk analysis can be useful tools to minimize the damage caused by sinkholes.
 National Geographic Society. “Sinkhole.” National Geographic Society, 9 Oct. 2012, www.nationalgeographic.org/encyclopedia/sinkhole.
 “Obruk nedir? Obruk ne demek?” Hürriyet, 21 Jan. 2020, www.hurriyet.com.tr/gundem/obruk-nedir-obruk-ne-demek-41424432.
 St. Johns River Water Management District. “How Sinkholes Form –.” SJRWMD, 18 Nov. 2020, www.sjrwmd.com/education/sinkholes.
 Wells, Sarah. “The Scary Science behind Mexico’s Massive Sinkhole.” Inverse, 3 June 2021, www.inverse.com/science/the-science-of-sink-holes.
 Wikipedia contributors. “Sinkhole.” Wikipedia, 1 Aug. 2021, en.wikipedia.org/wiki/Sinkhole#Natural_processes.