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70-756: Nettlebed Cave is a limestone cave located in the Mount Arthur region of the northwest South Island of New Zealand . The presence of ongaonga ( Urtica ferox ), an endemic tree nettle, near the bottom entrance gives the cave its name. Nettlebed Cave was connected to Stormy Pot in January 2014, making the system the deepest known cave in the Southern Hemisphere. Nettlebed Cave drops 1,180 metres (3,870 ft) below its upper entrance (Big Friendly Giant, Stormy Pot) to its lower exit (the Pearse River resurgence) and

140-581: A cave in 1934) can be directly associated to the exploration of the Dent de Crolles cave system. In 1941, American cavers organized themselves into the National Speleological Society (NSS) to advance the exploration, conservation, study and understanding of caves in the United States. American caver Bill Cuddington , known as "Vertical Bill", further developed the single-rope technique (SRT) in

210-399: A combination of chemical processes, erosion by water, tectonic forces, microorganisms, pressure, and atmospheric influences. Isotopic dating techniques can be applied to cave sediments, to determine the timescale of the geological events which formed and shaped present-day caves. It is estimated that a cave cannot be more than 3,000 metres (9,800 ft) vertically beneath the surface due to

280-417: A contrast between active and relict: active caves have water flowing through them; relict caves do not, though water may be retained in them. Types of active caves include inflow caves ("into which a stream sinks"), outflow caves ("from which a stream emerges"), and through caves ("traversed by a stream"). Solutional caves or karst caves are the most frequently occurring caves. Such caves form in rock that

350-542: A depth of 245 metres (804 ft) in the resurgence. 41°15′18″S 172°41′34″E  /  41.2550°S 172.6928°E  / -41.2550; 172.6928 Cave A cave or cavern is a natural void under the Earth 's surface . Caves often form by the weathering of rock and often extend deep underground. Exogene caves are smaller openings that extend a relatively short distance underground (such as rock shelters ). Caves which extend further underground than

420-442: A dissolution of existing features. Pollution is also of concern. Since water that flows through a cave eventually comes out in streams and rivers, any pollution may ultimately end up in someone's drinking water, and can even seriously affect the surface environment, as well. Even minor pollution such as dropping organic material can have a dramatic effect on the cave biota. Cave-dwelling species are also very fragile, and often,

490-503: A flexible metal ladder . In addition to the equipment already described, cavers frequently carry packs containing first-aid kits, emergency equipment, and food. Containers for securely transporting urine are also commonly carried. On longer trips, containers for securely transporting feces out of the cave are carried. During very long trips, it may be necessary to camp in the cave – some cavers have stayed underground for many days, or in particularly extreme cases, for weeks at

560-413: A guiding service (e.g. Lava River Cave , the oceanic islands of Tenerife , Iceland and Hawaii ). Caving has also been described as an "individualist's team sport" by some, as cavers can often make a trip without direct physical assistance from others but will generally go in a group for companionship or to provide emergency help if needed. Some however consider the assistance cavers give each other as

630-551: A hollow tube remains. Such caves can be found in the Canary Islands , Jeju-do , the basaltic plains of Eastern Idaho , and in other places. Kazumura Cave near Hilo , Hawaii is a remarkably long and deep lava tube; it is 65.6 km long (40.8 mi). Lava caves include but are not limited to lava tubes. Other caves formed through volcanic activity include rifts, lava molds, open vertical conduits, inflationary, blisters, among others. Sea caves are found along coasts around

700-420: A modern understanding of acoustics. Archaeologists have uncovered relationships between paintings of dots and lines, in specific areas of resonance, within the caves of Spain and France, as well as instruments depicting paleolithic motifs, indicators of musical events and rituals. Clusters of paintings were often found in areas with notable acoustics, sometimes even replicating the sounds of the animals depicted on

770-508: A pale or white coloration), a loss of eyes (or at least of optical functionality), an elongation of appendages, and an enhancement of other senses (such as the ability to sense vibrations in water). Aquatic troglobites (or stygobites), such as the endangered Alabama cave shrimp , live in bodies of water found in caves and get nutrients from detritus washed into their caves and from the feces of bats and other cave inhabitants. Other aquatic troglobites include cave fish, and cave salamanders such as

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840-525: A particular species found in a cave may live within that cave alone, and be found nowhere else in the world, such as Alabama cave shrimp . Cave-dwelling species are accustomed to a near-constant climate of temperature and humidity, and any disturbance can be disruptive to the species' life cycles. Though cave wildlife may not always be immediately visible, it is typically nonetheless present in most caves. Bats are one such fragile species of cave-dwelling animal. Bats which hibernate are most vulnerable during

910-534: A pristine floor of sand or silt which may be thousands of years old, dating from the last time water flowed through the cave. Such deposits may easily be spoiled forever by a single misplaced step. Active formations such as flowstone can be similarly marred with a muddy footprint or handprint, and ancient human artifacts, such as fiber products, may even crumble to dust under all but the most gentle touch. In 1988, concerned that cave resources were becoming increasingly damaged through unregulated use, Congress enacted

980-449: A range of early human species dating back to between three and one million years ago, including Australopithecus africanus , Australopithecus sediba and Paranthropus robustus . However, it is not generally thought that these early humans were living in the caves, but that they were brought into the caves by carnivores that had killed them. The first early hominid ever found in Africa,

1050-562: A rock hammer to emerge at the bottom of the urinal pitch for the Rover's Return bivvi (a low sandy passage used as a temporary campsite at one of Stormy Pot's further reaches). The team were extremely grateful for the NZSS policy of carrying out all solid human waste. The overall depth of the combined system (from the top entrance, Big Friendly Giant, to the deepest surveyed point in Nettlebed's Midas Chambers)

1120-513: A solutional cave that are below the water table or the local level of the groundwater will be flooded. Lechuguilla Cave in New Mexico and nearby Carlsbad Cavern are now believed to be examples of another type of solutional cave. They were formed by H 2 S ( hydrogen sulfide ) gas rising from below, where reservoirs of oil give off sulfurous fumes. This gas mixes with groundwater and forms H 2 SO 4 ( sulfuric acid ). The acid then dissolves

1190-424: A time. This is particularly the case when exploring or mapping extensive cave systems, where it would be impractical to retrace the route back to the surface regularly. Such long trips necessitate the cavers carrying provisions, sleeping, and cooking equipment. Caves can be dangerous places; hypothermia, falling , flooding , falling rocks and physical exhaustion are the main risks. Rescuing people from underground

1260-495: A typical team sport activity. The term potholing refers to the act of exploring potholes , a word originating in the north of England for predominantly vertical caves . Clay Perry , an American caver of the 1940s, wrote about a group of men and boys who explored and studied caves throughout New England . This group referred to themselves as spelunkers , a term derived from the Latin spēlunca ("cave, cavern, den"). This

1330-637: Is 48 kilometres (30 mi) long. Nettlebed Cave was first explored by cavers in 1969 through the dry overflow passage of a large spring pouring into the Pearse River. By 1973 1.3 kilometres (0.81 mi) of passages had been mapped. It was not until 1979 that a flowstone squeeze known as the Hinkle-horn-honking-holes was passed, making further explorations possible. Five successive Christmas expeditions (1979–80 through 1983–84) utilising underground camps at Salvation Hall and Soft Rock Cafe led to

1400-400: Is difficult and time-consuming, and requires special skills, training, and equipment. Full-scale cave rescues often involve the efforts of dozens of rescue workers (often other long-time cavers who have participated in specialized courses, as normal rescue staff are not sufficiently experienced in cave environments), who may themselves be put in jeopardy in effecting the rescue. This said, caving

1470-413: Is not necessarily a high-risk sport (especially if it does not involve difficult climbs or diving). As in all physical sports, knowing one's limitations is key. Caving in warmer climates carries the risk of contracting histoplasmosis , a fungal infection that is contracted from bird or bat droppings. It can cause pneumonia and can disseminate in the body to cause continued infections. In many parts of

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1540-488: Is often undertaken for the enjoyment of the outdoor activity or for physical exercise, as well as original exploration, similar to mountaineering or diving . Physical or biological science is also an important goal for some cavers, while others are engaged in cave photography. Virgin cave systems comprise some of the last unexplored regions on Earth and much effort is put into trying to locate, enter and survey them. In well-explored regions (such as most developed nations),

1610-568: Is regarded as the first use of the word in the Americas . Throughout the 1950s, spelunking was the general term used for exploring caves in US English . It was used freely, without any positive or negative connotations, although only rarely outside the US. In the 1960s, the terms spelunking and spelunker began to be considered déclassé among experienced enthusiasts. In 1985, Steve Knutson – editor of

1680-482: Is soluble; most occur in limestone , but they can also form in other rocks including chalk , dolomite , marble , salt, and gypsum . Except for salt caves , solutional caves result when rock is dissolved by natural acid in groundwater that seeps through bedding planes , faults , joints, and comparable features. Over time cracks enlarge to become caves and cave systems. The largest and most abundant solutional caves are located in limestone. Limestone dissolves under

1750-434: Is used, to provide some abrasion protection while remaining as cool as possible. Wetsuits may be worn if the cave is particularly wet or involves stream passages. On the feet boots are worn – hiking-style boots in drier caves, or rubber boots (such as wellies ) often with neoprene socks ("wetsocks") in wetter caves. Knee -pads (and sometimes elbow -pads) are popular for protecting joints during crawls. Depending on

1820-625: The Denisovans in southern Siberia. In southern Africa, early modern humans regularly used sea caves as shelter starting about 180,000 years ago when they learned to exploit the sea for the first time. The oldest known site is PP13B at Pinnacle Point . This may have allowed rapid expansion of humans out of Africa and colonization of areas of the world such as Australia by 60–50,000 years ago. Throughout southern Africa, Australia, and Europe, early modern humans used caves and rock shelters as sites for rock art, such as those at Giant's Castle . Caves such as

1890-507: The Dent de Crolles cave system near Grenoble , which became the deepest explored system in the world (-658m) at that time. The lack of available equipment during the war forced Pierre Chevalier and the rest of the team to develop their own equipment, leading to technical innovation. The scaling-pole (1940), nylon ropes (1942), use of explosives in caves (1947) and mechanical rope-ascenders (Henri Brenot's "monkeys", first used by Chevalier and Brenot in

1960-587: The Federal Cave Resources Protection Act , giving land management agencies in the United States expanded authority to manage cave conservation on public land. Cavers in many countries have created organizations for the administration and oversight of caving activities within their nations. The oldest of these is the French Federation of Speleology (originally Société de spéléologie) founded by Édouard-Alfred Martel in 1895, which produced

2030-777: The Madagascar dry deciduous forests and parts of Brazil contain many documented caves. As the world's expanses of soluble bedrock are researched by cavers, the distribution of documented caves is likely to shift. For example, China, despite containing around half the world's exposed limestone—more than 1,000,000 square kilometres (390,000 sq mi)—has relatively few documented caves. Cave-inhabiting animals are often categorized as troglobites (cave-limited species), troglophiles (species that can live their entire lives in caves, but also occur in other environments), trogloxenes (species that use caves, but cannot complete their life cycle fully in caves) and accidentals (animals not in one of

2100-426: The National Speleological Society (NSS) publication American Caving Accidents  – made the following distinction: …Note that (in this case) the term 'spelunker' denotes someone untrained and unknowledgeable in current exploration techniques, and 'caver' is for those who are. This sentiment is exemplified by bumper stickers and T-shirts displayed by some cavers: "Cavers rescue spelunkers". Nevertheless, outside

2170-588: The Taung Child in 1924, was also thought for many years to come from a cave, where it had been deposited after being predated on by an eagle. However, this is now debated (Hopley et al., 2013; Am. J. Phys. Anthrop.). Caves do form in the dolomite of the Ghaap Plateau, including the Early, Middle and Later Stone Age site of Wonderwerk Cave ; however, the caves that form along the escarpment's edge, like that hypothesised for

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2240-532: The olm and the Texas blind salamander . Cave insects such as Oligaphorura (formerly Archaphorura) schoetti are troglophiles, reaching 1.7 millimetres (0.067 in) in length. They have extensive distribution and have been studied fairly widely. Most specimens are female, but a male specimen was collected from St Cuthberts Swallet in 1969. Bats , such as the gray bat and Mexican free-tailed bat , are trogloxenes and are often found in caves; they forage outside of

2310-432: The rappel rack and the evolution of mechanical ascension systems extended the practice and safety of vertical exploration to a wider range of cavers. Hard hats are worn to protect the head from bumps and falling rocks. The caver's primary light source is usually mounted on the helmet in order to keep the hands free. Electric LED lights are most common. Many cavers carry two or more sources of light – one as primary and

2380-456: The very slow flow of the ice, which tends to collapse the caves again. Glacier caves are sometimes misidentified as " ice caves ", though this latter term is properly reserved for bedrock caves that contain year-round ice formations. Fracture caves are formed when layers of more soluble minerals, such as gypsum, dissolve out from between layers of less soluble rock. These rocks fracture and collapse in blocks of stone. Talus caves are formed by

2450-514: The yaodong in China were used for shelter; other caves were used for burials (such as rock-cut tombs ), or as religious sites (such as Buddhist caves ). Among the known sacred caves are China's Cave of a Thousand Buddhas and the sacred caves of Crete . Paleolithic cave paintings have been found throughout the world dating from 64,800 years old for non-figurative art and 43,900 years old for figurative art. The importance of sound in caves predates

2520-801: The 1890s, Balch was introduced to the caves of the Mendip Hills . One of the oldest established caving clubs, Yorkshire Ramblers' Club , was founded in 1892. Caving as a specialized pursuit was pioneered by Édouard-Alfred Martel (1859–1938), who first achieved the descent and exploration of the Gouffre de Padirac , in France, as early as 1889 and the first complete descent of a 110-metre wet vertical shaft at Gaping Gill in 1895. He developed his own techniques based on ropes and metallic ladders. Martel visited Kentucky and notably Mammoth Cave National Park in October 1912. In

2590-713: The 1920s famous US caver Floyd Collins made important explorations in the area and in the 1930s, as caving became increasingly popular, small exploration teams both in the Alps and in the karstic high plateaus of southwest France ( Causses and Pyrenees ) transformed cave exploration into both a scientific and recreational activity. Robert de Joly , Guy de Lavaur and Norbert Casteret were prominent figures of that time, surveying mostly caves in Southwest France. During World War II , an alpine team composed of Pierre Chevalier , Fernand Petzl , Charles Petit-Didier and others explored

2660-533: The Ellis Basin to the south, from Windrift to the west, and from Nettlebed Cave itself. On 21 March 2007, a team of international cave divers set a New Zealand cave diving record by reaching a depth of 177m (581 feet below ground level) in the Pearse Resurgence. In 2011, divers reached 194 metres (636 ft) depth by placing four decompression habitats along the cave main tunnel but were still unable to trace

2730-460: The Nettlebed side on 29 February 2014, at the end of a week-long camp at Soft Rock Cafe. After a kerosene smoke test had previously indicated a likely point of connection, a team of four (Kieran McKay, Bruce Mutton, Gavin Holden and Jonathan Ravens) dug out the rubble from a choked, drafting, rift to reach the bottom of a small muddy shaft. A tight squeeze at the top of this climb was enlarged slightly with

2800-755: The Taung Child, are formed within a secondary limestone deposit called tufa . There is numerous evidence for other early human species inhabiting caves from at least one million years ago in different parts of the world, including Homo erectus in China at Zhoukoudian , Homo rhodesiensis in South Africa at the Cave of Hearths ( Makapansgat ), Homo neanderthalensis and Homo heidelbergensis in Europe at Archaeological Site of Atapuerca , Homo floresiensis in Indonesia, and

2870-461: The UK and other European countries, although in the US they are generally more private. Although caving is sometimes categorized as an " extreme sport ," cavers do not commonly use this terminology and typically dislike the term being used in reference to caving, as it implies a disregard for safety. Many caving skills overlap with those involved in canyoning and mine and urban exploration . Caving

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2940-552: The action of rainwater and groundwater charged with H 2 CO 3 ( carbonic acid ) and naturally occurring organic acids . The dissolution process produces a distinctive landform known as karst , characterized by sinkholes and underground drainage. Limestone caves are often adorned with calcium carbonate formations produced through slow precipitation . These include flowstones , stalactites , stalagmites , helictites , soda straws and columns. These secondary mineral deposits in caves are called speleothems . The portions of

3010-578: The caves utilized for reverberation, but for the dampening qualities of their abnormal faces as well. The irregularities in the walls of the Cumberland Caverns diffuse sounds bouncing off the walls and give the space an almost recording studio-like quality. During the 20th century musicians began to explore the possibility of using caves as locations as clubs and concert halls, including the likes of Dinah Shore , Roy Acuff , and Benny Goodman . Unlike today, these early performances were typically held in

3080-561: The caves. Some species of cave crickets are classified as trogloxenes, because they roost in caves by day and forage above ground at night. Because of the fragility of cave ecosystems, and the fact that cave regions tend to be isolated from one another, caves harbor a number of endangered species, such as the Tooth cave spider , liphistius trapdoor spider , and the gray bat. Caves are visited by many surface-living animals, including humans. These are usually relatively short-lived incursions, due to

3150-462: The caving community, "spelunking" and "spelunkers" predominately remain neutral terms referring to the practice and practitioners, without any respect to skill level. In the mid-nineteenth century, John Birkbeck explored potholes in England, notably Gaping Gill in 1842 and Alum Pot in 1847–8, returning there in the 1870s. In the mid-1880s, Herbert E. Balch began exploring Wookey Hole Caves and in

3220-498: The entrance, negotiating pitches , squeezes, and water hazards can be difficult. Cave diving is a distinct, and more hazardous, sub-speciality undertaken by a small minority of technically proficient cavers. In an area of overlap between recreational pursuit and scientific study, the most devoted and serious-minded cavers become accomplished at the surveying and mapping of caves and the formal publication of their efforts. These are usually published freely and publicly, especially in

3290-444: The environment of the cave being explored, and the local culture. In cold caves, the caver may wear a warm base layer that retains its insulating properties when wet, such as a fleece ("furry") suit or polypropylene underwear, and an oversuit of hard-wearing (e.g., cordura ) or waterproof (e.g., PVC ) material. Lighter clothing may be worn in warm caves, particularly if the cave is dry, and in tropical caves thin polypropylene clothing

3360-511: The exploration and mapping of a further 20 kilometres (12 mi). In 1986 another cave (Blizzard Pot) was connected with Nettlebed Cave, providing an upper entrance to the system, and made the overall depth 889 metres (2,917 ft) from the highest point in Blizzard Pot to the deepest point in Nettlebed Cave. The long-sought-after connection between Nettlebed and Stormy Pot was made from

3430-472: The first periodical journal in speleology, Spelunca . The first University-based speleological institute in the world was founded in 1920 in Cluj-Napoca , Romania, by Emil Racovita , a Romanian biologist, zoologist, speleologist and explorer of Antarctica. The British Speleological Association was established in 1935 and the National Speleological Society in the US was founded in 1941 (originally formed as

3500-562: The lack of light and sustenance. Cave entrances often have typical florae. For instance, in the eastern temperate United States, cave entrances are most frequently (and often densely) populated by the bulblet fern, Cystopteris bulbifera . People have made use of caves throughout history. The earliest human fossils found in caves come from a series of caves near Krugersdorp and Mokopane in South Africa. The cave sites of Sterkfontein , Swartkrans , Kromdraai B, Drimolen , Malapa , Cooper's D, Gladysvale, Gondolin and Makapansgat have yielded

3570-621: The late 1950s. In 1958, two Swiss alpinists, Juesi and Marti teamed together, creating the first rope ascender known as the Jumar . In 1968 Bruno Dressler asked Fernand Petzl, who worked as a metals machinist, to build a rope-ascending tool, today known as the Petzl Croll , that he had developed by adapting the Jumar to vertical caving. Pursuing these developments, Petzl started in the 1970s a caving equipment manufacturing company named Petzl . The development of

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3640-413: The limestone from below, rather than from above, by acidic water percolating from the surface. Caves formed at the same time as the surrounding rock are called primary caves . Lava tubes are formed through volcanic activity and are the most common primary caves. As lava flows downhill, its surface cools and solidifies. Hot liquid lava continues to flow under that crust, and if most of it flows out,

3710-555: The most accessible caves have already been explored, and gaining access to new caves often requires cave digging or cave diving. Caving, in certain areas, has also been utilized as a form of eco and adventure tourism, for example in New Zealand . Tour companies have established an industry leading and guiding tours into and through caves. Depending on the type of cave and the type of tour, the experience could be adventure-based or ecological-based. There are tours led through lava tubes by

3780-414: The mouths of the caves, as the lack of technology made depths of the interior inaccessible with musical equipment. In Luray Caverns , Virginia, a functioning organ has been developed that generates sound by mallets striking stalactites, each with a different pitch. Caving The challenges involved in caving vary according to the cave being visited; in addition to the total absence of light beyond

3850-610: The nature of the cave, gloves are sometimes worn to protect the hands against abrasion or cold. In pristine areas and for restoration, clean oversuits and powder-free, non-latex surgical gloves are used to protect the cave itself from contaminants. Ropes are used for descending or ascending pitches (single rope technique or SRT) or for protection. Knots commonly used in caving are the figure-of-eight - (or figure-of-nine -) loop, bowline , alpine butterfly , and Italian hitch . Ropes are usually rigged using bolts , slings , and carabiners . In some cases cavers may choose to bring and use

3920-476: The opening is wide are called endogene caves . Speleology is the science of exploration and study of all aspects of caves and the cave environment. Visiting or exploring caves for recreation may be called caving , potholing , or spelunking . The formation and development of caves is known as speleogenesis ; it can occur over the course of millions of years. Caves can range widely in size, and are formed by various geological processes. These may involve

3990-465: The openings among large boulders that have fallen down into a random heap, often at the bases of cliffs. These unstable deposits are called talus or scree , and may be subject to frequent rockfalls and landslides . Anchialine caves are caves, usually coastal, containing a mixture of freshwater and saline water (usually sea water). They occur in many parts of the world, and often contain highly specialized and endemic fauna. Caves are found throughout

4060-430: The others as backup in case the first fails. More often than not, a second light will be mounted to the helmet for quick transition if the primary fails. Carbide lamp systems are an older form of illumination, inspired by miner's equipment, and are still used by some cavers, particularly on remote expeditions where electric charging facilities are not available. The type of clothes worn underground varies according to

4130-549: The pressure of overlying rocks. This does not, however, impose a maximum depth for a cave which is measured from its highest entrance to its lowest point, as the amount of rock above the lowest point is dependent on the topography of the landscape above it. For karst caves the maximum depth is determined on the basis of the lower limit of karst forming processes, coinciding with the base of the soluble carbonate rocks. Most caves are formed in limestone by dissolution . Caves can be classified in various other ways as well, including

4200-428: The previous categories). Some authors use separate terminology for aquatic forms (for example, stygobites , stygophiles , and stygoxenes ). Of these animals, the troglobites are perhaps the most unusual organisms. Troglobitic species often show a number of characteristics, termed troglomorphic, associated with their adaptation to subterranean life. These characteristics may include a loss of pigment (often resulting in

4270-469: The slightest touch and some by impacts as slight as a breath. Research suggests that increased carbon dioxide levels can lead to "a higher equilibrium concentration of calcium within the drip waters feeding the speleothems, and hence causes dissolution of existing features." In 2008, researchers found evidence that respiration from cave visitors may generate elevated carbon dioxide concentrations in caves, leading to increased temperatures of up to 3 °C and

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4340-466: The source. During the 2014 Wet Mules diving expedition, the Pearse was dived to a record depth of −217 metres (−712 ft). In 2016, Richard Harris and Dave Hurst pushed the limits of the main spring with a 13-hour dive to explore the "Second Breakfast" passage to a depth of 229 metres (751 ft) before lights began to implode causing them to turn back. In 2020, Richard Harris and Craig Challen reached

4410-462: The walls. The human voice was also theorized to be used as an echolocation device to navigate darker areas of the caves where torches were less useful. Dots of red ochre are often found in spaces with the highest resonance, where the production of paintings was too difficult. Caves continue to provide usage for modern-day explorers of acoustics. Today Cumberland Caverns provides one of the best examples for modern musical usages of caves. Not only are

4480-659: The warmer months when they are most sensitive and vulnerable. Due to an affliction affecting bats in the northeastern US known as white nose syndrome (WNS), the US Fish & Wildlife Service has called for a moratorium effective March 26, 2009, on caving activity in states known to have hibernacula (MD, NY, VT, NH, MA, CT, NJ, PA, VA, and WV) affected by WNS, as well as adjoining states. Some cave passages may be marked with flagging tape or other indicators to show biologically, aesthetically, or archaeologically sensitive areas. Marked paths may show ways around notably fragile areas such as

4550-417: The water, such as a fault or joint. A subtype of the erosional cave is the wind or aeolian cave, carved by wind-born sediments. Many caves formed initially by solutional processes often undergo a subsequent phase of erosional or vadose enlargement where active streams or rivers pass through them. Glacier caves are formed by melting ice and flowing water within and under glaciers. The cavities are influenced by

4620-408: The winter season, when no food supply exists on the surface to replenish the bat's store of energy should it be awakened from hibernation. Bats which migrate are most sensitive during the summer months when they are raising their young. For these reasons, visiting caves inhabited by hibernating bats is discouraged during cold months; and visiting caves inhabited by migratory bats is discouraged during

4690-427: The world, leptospirosis ("a type of bacterial infection spread by animals" including rats ) is a distinct threat, owing to the presence of rat urine in rainwater or precipitation that enters the caves water system. Complications are uncommon, but can be serious. Safety risks while caving can be minimized by using a number of techniques: Many cave environments are very fragile. Many speleothems can be damaged by even

4760-549: The world, although the distribution of documented cave system is heavily skewed towards those countries where caving has been popular for many years (such as France, Italy, Australia, the UK, the United States, etc.). As a result, explored caves are found widely in Europe, Asia, North America and Oceania, but are sparse in South America, Africa, and Antarctica. This is a rough generalization, as large expanses of North America and Asia contain no documented caves, whereas areas such as

4830-791: The world. A special case is littoral caves, which are formed by wave action in zones of weakness in sea cliffs. Often these weaknesses are faults, but they may also be dykes or bedding-plane contacts. Some wave-cut caves are now above sea level because of later uplift. Elsewhere, in places such as Thailand 's Phang Nga Bay , solutional caves have been flooded by the sea and are now subject to littoral erosion. Sea caves are generally around 5 to 50 metres (16 to 164 ft) in length, but may exceed 300 metres (980 ft). Corrasional or erosional caves are those that form entirely by erosion by flowing streams carrying rocks and other sediments. These can form in any type of rock, including hard rocks such as granite. Generally there must be some zone of weakness to guide

4900-605: Was later confirmed as 1,180 metres (3,870 ft) when an accurate GPS survey of the entrance locations was undertaken in December 2015. As of December 2019, the total surveyed length of Nettlebed/Stormy Pot is 47,969.7 metres (157,381 ft). The Pearse Resurgence is the source of the Pearse Stream, and is the resurgence point for all caves on Mt Arthur, including all water flowing in Nettlebed Cave (under normal water levels). This has been confirmed by positive dye tests from caves in

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