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The law was amended in 1990 to allow funds to be spent on the reclamation of mines abandoned after 1977. The fund is financed by a tax of 31.5 cents per ton for surface mined coal, 15 cents per ton for coal mined underground, and 10 cents per ton for lignite. 80% of AML fees are distributed to states with an approved reclamation program (see ...
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.
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A subsidence crater is a hole or depression left on the surface of an area which has had an underground (usually nuclear) explosion. Many such craters are commonly present at bomb testing areas; one notable example is the Nevada Test Site , which was historically used for nuclear weapons testing over a period of 41 years.
Groundwater use and pumping in the area was the major water use for farmers and agriculture in the 1920s, and over time, this over-pumping resulted in land subsidence and a decline in groundwater-level resources. In time, this resulted in major land subsidence by the 1970s with local areas having 0.30 to 8.5 m (1 to 28 ft) of subsidence.
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.
The Neil George Safety System (or 5-Point Safety System) is an occupational health and safety program developed for and used in underground mining. The system was developed in 1942 by Canadian engineer Neil George, who at the time was an employee of Inco Limited in Sudbury, Ontario. The program is used throughout Canada and internationally. [1] [2]