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The Red Lake sinkhole in Croatia. A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are also known as shakeholes, and to openings where surface water enters into underground passages known as ponor, swallow hole or swallet.
Subsidence frequently causes major problems in karst terrains, where dissolution of limestone by fluid flow in the subsurface creates voids (i.e., caves).If the roof of a void becomes too weak, it can collapse and the overlying rock and earth will fall into the space, causing subsidence at the surface.
[2] [1] Suffosion sinkholes are normally associated with karst topography although they may form in other types of rock including chalk, gypsum and basalt. In the karst of the UK's Yorkshire Dales, numerous surface depressions known locally as "shakeholes" are the result of glacial till washing into fissures in the underlying limestone.
Sinkholes can be classified on the basis of the processes by which they are formed: dissolution, cover-subsidence, and cover-collapse. Formation of sinkholes can be accelerated by intense withdrawals of groundwater over short periods of time, such as those caused by pumping for frost-protection of winter crops in west-central Florida.
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Drivers, processes, and impacts of sinking cities [1]. Sinking cities are urban environments that are in danger of disappearing due to their rapidly changing landscapes.The largest contributors to these cities becoming unlivable are the combined effects of climate change (manifested through sea level rise, intensifying storms, and storm surge), land subsidence, and accelerated urbanization. [2]
Cenote, a deep sinkhole, characteristic of Mexico, resulting from collapse of limestone bedrock that exposes groundwater underneath; Doline, also sink or sinkhole, is a closed depression draining underground in karst areas. The name "doline" comes from dolina, meaning "valley", and derives from South Slavic languages.
Tectonic subsidence is the sinking of the Earth's crust on a large scale, relative to crustal-scale features or the geoid. [1] The movement of crustal plates and accommodation spaces produced by faulting [2] brought about subsidence on a large scale in a variety of environments, including passive margins, aulacogens, fore-arc basins, foreland basins, intercontinental basins and pull-apart basins.