A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word cave can refer to smaller openings such as sea caves, rock shelters, and grottos, that extend a relatively short distance into the rock and they are called exogene caves. Caves which extend further underground than the opening is wide are called endogene caves.
Lake Nyos is a crater lake in the Northwest Region of Cameroon, located about 315 km (196 mi) northwest of Yaoundé, the capital. Nyos is a deep lake high on the flank of an inactive volcano in the Oku volcanic plain along the Cameroon line of volcanic activity. A volcanic dam impounds the lake waters.
Travertine is a form of terrestrial limestone deposited around mineral springs, especially hot springs. It often has a fibrous or concentric appearance and exists in white, tan, cream-colored, and rusty varieties. It is formed by a process of rapid precipitation of calcium carbonate, often at the mouth of a hot spring or in a limestone cave. In the latter, it can form stalactites, stalagmites, and other speleothems. It is frequently used in Italy and elsewhere as a building material. Similar deposits formed from ambient-temperature water are known as tufa.
Total organic carbon (TOC) is an analytical parameter representing the concentration of organic carbon in a sample. TOC determinations are made in a variety of application areas. For example, TOC may be used as a non-specific indicator of water quality, or TOC of source rock may be used as one factor in evaluating a petroleum play. For marine surface sediments average TOC content is 0.5% in the deep ocean, and 2% along the eastern margins.
The Marble Arch Caves are a series of natural limestone caves located near the village of Florencecourt in County Fermanagh, Northern Ireland. The caves are named after the nearby Marble Arch, a natural limestone arch at the upstream end of Cladagh Glen under which the Cladagh River flows. The caves are formed from three rivers draining off the northern slopes of Cuilcagh mountain, which combine underground to form the Cladagh. On the surface, the river emerges from the largest karst resurgence in Ireland, and one of the largest in the United Kingdom. At 11.5 kilometres (7.1 mi) the Marble Arch Caves form the longest known cave system in Northern Ireland, and the karst is considered to be among the finest in the British Isles.
A blue hole is a large marine cavern or sinkhole, which is open to the surface and has developed in a bank or island composed of a carbonate bedrock. Blue holes typically contain tidally influenced water of fresh, marine, or mixed chemistry. They extend below sea level for most of their depth and may provide access to submerged cave passages. Well-known examples are the Dragon Hole and, in the Caribbean, the Great Blue Hole and Dean's Blue Hole.
Troglofauna are small cave-dwelling animals that have adapted to their dark surroundings. Troglofauna and stygofauna are the two types of subterranean fauna. Both are associated with subterranean environments – troglofauna are associated with caves and spaces above the water table and stygofauna with water. Troglofaunal species include spiders, insects, myriapods and others. Some troglofauna live permanently underground and cannot survive outside the cave environment. Troglofauna adaptations and characteristics include a heightened sense of hearing, touch and smell. Loss of under-used senses is apparent in the lack of pigmentation as well as eyesight in most troglofauna. Troglofauna insects may exhibit a lack of wings and longer appendages.
Dos Ojos is part of a flooded cave system located north of Tulum, on the Caribbean coast of the Yucatán Peninsula, in the state of Quintana Roo, Mexico. The exploration of Dos Ojos began in 1987 and still continues. The surveyed extent of the cave system is 82 kilometers (51 mi) and there are 28 known sinkhole entrances, which are locally called cenotes. In January 2018, a connection was found between Sistema Dos Ojos and Sistema Sac Actun. The smaller Dos Ojos became a part of Sac Actun, making the Sistema Sac Actun the longest known underwater cave system in the world.
Carlsbad Caverns National Park is an American national park in the Guadalupe Mountains of southeastern New Mexico. The primary attraction of the park is the show cave Carlsbad Cavern. Visitors to the cave can hike in on their own via the natural entrance or take an elevator from the visitor center.
Speleogenesis is the origin and development of caves, the primary process that determines essential features of the hydrogeology of karst and guides its evolution. It often deals with the development of caves through limestone, caused by the presence of water with carbon dioxide dissolved within it, producing carbonic acid which permits the dissociation of the calcium carbonate in the limestone.
Windsor Great Cave is a 3,000 metres (9,800 ft) long cave in Trelawny Parish on the north coast of Jamaica. The land external to the main entrance is owned by the WWF (UK), and access is often denied by the Windsor Research Centre who act as their proxy.
Sơn Đoòng cave, in Phong Nha-Kẻ Bàng National Park, Bố Trạch District, Quảng Bình Province, Vietnam, is one of the world's largest natural caves.
Photosynthesis systems are electronic scientific instruments designed for non-destructive measurement of photosynthetic rates in the field. Photosynthesis systems are commonly used in agronomic and environmental research, as well as studies of the global carbon cycle.
Gökgöl Cave is a show cave in Zonguldak Province, Turkey. It is the fifth biggest cave of the country. It is close to a main highway and is well-decorated with stalactites and stalagmites and attracts many visitors.
Short Drop Cave and Gavel Pot are different entrances into the same cave system on Leck Fell, in Lancashire, England. The main top entrance, Short Drop Cave, is a small hole in a fenced off shakehole near the main stream sink; Gavel Pot, a window into the system, is a large fenced shakehole some 40-metre (130 ft) deep requiring tackle to descend. There are two other smaller entrances into Short Drop Cave. At its base the system links via a sump with Lost Johns' Cave, and is part of the Three Counties System, an 87 kilometres (54 mi) cave system which spans the borders of Cumbria, Lancashire, and North Yorkshire.
Stream Passage Pot is one of the entrances to the Gaping Gill system being located about 320 metres (350 yd) ESE of Gaping Gill Main Shaft. It is a popular and sporting entrance into the system, featuring three well-watered big shafts. It is the highest entrance of the Gaping Gill system, so the full depth of the system, 198 metres (650 ft), is measured from its entrance. It lies within the designated Ingleborough Site of Special Scientific Interest.
Little Blue Lake is a water-filled sinkhole (“cenote”) in the Australian state of South Australia located in the state's south-east in the locality of Mount Schank about 20 kilometres (12 mi) south of the municipal seat of Mount Gambier. It is notable locally as a swimming hole and nationally as a cave diving site. It is managed by the District Council of Grant and has been developed as a recreational and tourism venue.
Engelbrecht Cave is a cave system in the Australian state of South Australia consisting of a sinkhole with two major passages located under the Mount Gambier urban area. It is owned by the local government area of City of Mount Gambier and has been developed as a tourism venue. Its dry extent is notable as a show cave while its water-filled extent is notable as two separate cave diving sites.
Kitley Show Cave is a solution cave in Yealmpton, Devon, England. Originally discovered by quarrying, it used to be open to the public as a show cave, but is now closed.
Total inorganic carbon is the sum of the inorganic carbon species.
