New Delhi:
Sinkholes are depressions or holes in the land surface that occur when underlying rocks dissolve. They are common in areas where the rocks below the land surface can naturally be dissolved by ground water circulating through them such as limestone, carbonate rock or salt beds.
As rain falls through the atmosphere, it absorbs carbon dioxide and forms a weak carbonic acid. This water moves through the soil zone and reacts with living and decaying plant matter and becomes more acidic. The acidic water slowly dissolves limestone, especially along the fractures and weak layers.
The process of chemical dissolution of carbonate rocks is called the Karst Process. As the rock dissolves, spaces and caverns develop underground.
The land usually stays intact for a while until the underground spaces just get too big. If there is not enough support for the land above the spaces then a sudden collapse of the land surface can occur making sinkholes a rather dramatic natural phenomenon.
Occasionally, a sinkhole may exhibit a visible opening into a cave below. In the case of exceptionally large sinkholes, a stream or river may be visible across its bottom flowing from one side to the other.
Also known as swallow hole, swallet, doline,or cenote, these may be formed gradually or suddenly and may vary in size and form.
Hydrologic conditions, including lack of rainfall, lowered water levels, or, conversely, excessive rainfall in a short period of time, can contribute to sinkhole development. However, sinkholes can also be human-induced.
Infact, many new sinkholes have been correlated to land-use practices, especially ground-water pumping, construction, and development practices.
Some sinkholes form when the land surface is changed and the substantial weight of the new material can trigger an underground collapse of supporting material, thus, causing a sinkhole.
Sinkholes have been used for centuries as disposal sites for various forms of waste. However, this has gradually led to the pollution of groundwater resources, with serious health implications in such areas.
As rain falls through the atmosphere, it absorbs carbon dioxide and forms a weak carbonic acid. This water moves through the soil zone and reacts with living and decaying plant matter and becomes more acidic. The acidic water slowly dissolves limestone, especially along the fractures and weak layers.
The process of chemical dissolution of carbonate rocks is called the Karst Process. As the rock dissolves, spaces and caverns develop underground.
The land usually stays intact for a while until the underground spaces just get too big. If there is not enough support for the land above the spaces then a sudden collapse of the land surface can occur making sinkholes a rather dramatic natural phenomenon.
Occasionally, a sinkhole may exhibit a visible opening into a cave below. In the case of exceptionally large sinkholes, a stream or river may be visible across its bottom flowing from one side to the other.
Also known as swallow hole, swallet, doline,or cenote, these may be formed gradually or suddenly and may vary in size and form.
Hydrologic conditions, including lack of rainfall, lowered water levels, or, conversely, excessive rainfall in a short period of time, can contribute to sinkhole development. However, sinkholes can also be human-induced.
Infact, many new sinkholes have been correlated to land-use practices, especially ground-water pumping, construction, and development practices.
Some sinkholes form when the land surface is changed and the substantial weight of the new material can trigger an underground collapse of supporting material, thus, causing a sinkhole.
Sinkholes have been used for centuries as disposal sites for various forms of waste. However, this has gradually led to the pollution of groundwater resources, with serious health implications in such areas.
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