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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.
Groundwater-related subsidence is the subsidence (or the sinking) of land resulting from unsustainable groundwater extraction.It is a growing problem in the developing world as cities increase in population and water use, without adequate pumping regulation and enforcement.
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.
where is the tectonically driven subsidence, is the decompacted sediment thickness, is the mean sediment density, is the average depth at which the sedimentary units were deposited, and are the densities of the water and mantle respectively, and the difference in sea-level height between the Present and the time at which the sediments were deposited.
Key components of studying land subsidence in the Central Valley include large and small scale monitoring, studying topography in relation to groundwater, and a multi-agency approach. Discoveries made by monitoring may allow for better mitigation practices and policies to prevent subsidence.
This includes the use of differential GPS and SAR remote sensing to monitor the risks imposed by landslides and subsidence. For large dams, seismographs are used to detect reservoir-induced seismicity that could threaten the stability of the dam. [1] The output of these systems can provide warning to the local population ahead of a potential ...
A pit crater (also called a subsidence crater or collapse crater) is a depression formed by a sinking or collapse of the surface lying above a void or empty chamber, rather than by the eruption of a volcano or lava vent. [1] Pit craters are found on Mercury, Venus, [2] [3] Earth, Mars, [4] and the Moon. [5]
The Intergovernmental Council for the International Hydrological Programme (IHP) created a Working Group on Land Subsidence for liaison of IHP subproject 8.4, "Investigation on land subsidence due to ground-water exploitation." in April 1975. [2] This first WGLS was composed by: Mr. Joseph F. Poland, Chairman. U.S. Geological Survey, USA. (Chair)