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CAVE
CAVE
From Wikipedia, the free encyclopedia
(Redirec
ted fro
m Caves) 
Jump to: navigation, search
Lechuguilla Cave, New Mexico
For other uses, see Cave (disambiguation).
A cave is a natural underground void large enough for a human to enter. Some people suggest that the term cave should only apply to cavities that have some part that does not receive daylight; however, in popular usage, the term includes sm
aller spaces like sea caves, rock shelters, and grottos.
Speleology is
the science of exploration and study of all aspects of caves. Exploring a cave for recreation or science may be called caving, potholing, or occasionally (only in Canada and the United States), spelunking (see Caving).
Contents[hide]
1 Types and formation
2 Patterns
3 Geographic distribution
4 Record lengths, depths, pitches and volumes
5 Ecology
6 Archaeological and social importance
7 See also
8 References
9 External links
//
[edit] Types and formation
The formation and development of caves is known as speleogenesis. Caves are formed by various geologic processes. These may involve a combination of chemical processes, erosion from water, tectonic forces, microorganisms, pressure, atmospheric influences, and even digging.
Most caves are formed in limestone by dissolution.
Speleothems in Hall of the Mountain King, Ogof Craig a Ffynnon, South Wales.
Solutional caves may form anywhere with rock that is soluble, and are most prevalent in limestone, but can also form in other material, including chalk, dolomite, marble, granite, salt, sandstone, fossilized coral and gypsum.
The largest and most abundant solutional caves are located in limestone. Limestone dissolves under the action of rainwater and groundwater charged with H2CO3 (carbonic acid) and naturally occurring organic acids. The dissolution process produces a distinctive landform known as karst, characterized by sinkholes, sinking streams, and underground drainage. Limestone caves are often adorned with calcium carbonate formations produced through slow precipitation. This include: flowstones, stalactites, stalagmites, helictites, draperies, soda straws and columns. These secondary mineral deposits in caves are called speleothems.
The world's most spectacularly decorated cave is generally regarded to be Lechuguilla Cave in New Mexico. Lechuguilla and nearby Carlsbad Caverns are now believed to be examples of another type of solutional cave. They were formed by H2S (hydrogen sulfide) gas rising from below, where reservoirs of oil give off sulfurous fumes. This gas mixes with ground water and forms H2SO4 (sulfuric acid). The acid then dissolves the limestone from below, rather than from above, by acidic water percolating from the surface.
Exploring a lava tube in Hawaii
Some caves are formed at the same time as the surrounding rock. These are sometimes called primary caves.
Lava tubes are formed through volcanic activity and are the most common 'primary' caves. The lava flows downhill and the surface cools and solidifies. The hotter lava continues to flow under that crust, and if most of the liquid lava beneath the crust flows out, a hollow tube remains, thus forming a cavity. Examples of such caves can be found on Tenerife, Big Island, and many other places. Kazumura Cave near Hilo is a remarkably long and deep lava tube; it is 65.6 kilometers (40.8 mi) long.
Blister caves are also formed through volcanic activity.
Painted Cave, a large sea cave, Santa Cruz Island, California
Sea caves are found along coasts around 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 meters (16 ft) to 50 meters (160 ft) in length but may exceed 300 meters (980 ft).
Glacier cave in Big Four Glacier, Big Four Mountain, Washington, ca. 1920.
Glacier caves occur in ice and under glaciers and are formed by melting. They are also influenced by the very slow flow of the ice, which tends to close the caves again. (These are sometimes called ice caves, though this term is properly reserved for 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.
Talus caves are the openings between rocks that have fallen down into a pile, often at the bases of cliffs.
Anchihaline 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 faunas.
[edit] Patterns
Branchwork caves resemble surface dentritic stream patterns; they are made up of passages that join downstream as tributaries. Branchwork caves are the most common of cave patterns and are formed near sinkholes where groundwater recharge occurs. Each passage or branch is fed by a separate recharge source and converges into other higher order branches downstream.[1]
Angular Network caves form from intersecting fissures of carbonate rock that have had fractures widened by chemical erosion. These fractures form high, narrow, straight passages that persist in widespread closed loops.[1]
Anastomotic caves largely resemble surface braided streams with their passages separating and then meeting further down drainage. They usually form along one bed or structure, and only rarely cross into upper or lower beds.[1]
Spongework caves are formed as solution cavities are joined by mixing of chemically diverse water. The cavities form a pattern that is three-dimensional and random, resembling a sponge.[1]
Ramiform caves form as irregular large rooms, galleries, and passages. These randomized three-dimensional rooms form from a rising water table that erodes the carbonate rock with hydrogen-sulfide enriched water.[1]
[edit] Geographic distribution
Caves are found throughout the world, but only a portion of them have been explored and documented by cavers. The distribution of documented cave systems is widely skewed toward 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 great generalization, as large expanses of North America and Asia contain no documented caves, whereas areas such as 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 kilometers (390,000 sq mi) - has relatively few documented caves.
[edit] Record lengths, depths, pitches and volumes
Canyon passage in Mammoth Cave, the world's longest cave.
The cave system with the greatest total length of passage is Mammoth Cave (Kentucky, USA) at 591 kilometers (367 mi) in length. This record is unlikely to be surpassed in the near future, as the next most extensive known cave is Jewel Cave near Custer, South Dakota, at 225 kilometers (140 mi).[2]
The deepest known cave (measured from its highest entrance to its lowest point) is Voronya Cave (Abkhazia, Georgia), with a depth of 2,191 meters (7,190 ft).[3] This was the first cave to be explored to a depth of more than 2 kilometers (1.2 mi). (The first cave to be descended below 1 kilometer (0.62 mi) was the famous Gouffre Berger in France). The Illyuzia-Mezhonnogo-Snezhnaya cave in Abkhazia, Georgia, (1,753 meters (5,750 ft)) and the Lamprechtsofen Vogelschacht Weg Schacht in Austria (1,632 meters (5,350 ft)) are the current second- and third-deepest caves. This particular record has changed several times in recent years.
The deepest individual pitch (vertical drop) within a cave is 603 meters (1,980 ft) in Vrtoglavica Cave in Slovenia, followed by Patkov Gušt at 553 meters (1,810 ft) in the Velebit mountain, Croatia.
The largest individual cavern ever discovered is the Sarawak chamber, in the Gunung Mulu National Park (Miri, Sarawak, Borneo, Malaysia), a sloping, boulder strewn chamber with an area of approximately 600 meters (2,000 ft) by 400 meters (1,300 ft) and a height of 80 meters (260 ft).
[edit] Ecology
Townsend's Big-eared bats in a cave
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 wholly in caves) and accidentals (animals not in one of the previous categories). Some authors use separate terminology for aquatic forms (e.g., stygobites, stygophiles, and stygoxenes).
Of these animals, the troglobites are perhaps the most unusual organisms. Troglobitic species often show a number of characteristics, termed troglomorphies, associated with their adaptation to subterranean life. These characteristics may include a loss of pigment (often resulting in 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, the Olm, and cave salamanders such as the Texas Blind Salamander.
Cave insects such as Oligaphorura (formerly Archaphorura) schoetti are troglophiles, reaching 1.7 millimeters (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 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 fragile nature of the cave ecosystem, 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, Liphistiidae 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 the lack of light and sustenance.
[edit] Archaeological and social importance
Taino petroglyphs in a cave in Puerto Rico
Throughout history, primitive peoples have made use of caves for shelter, burial, or as religious sites. Since items placed in caves are protected from the climate and scavenging animals, this means caves are an archaeological treasure house for learning about these people. Cave paintings are of particular interest. One example is the Great Cave of Niah, in Malaysia, which contains evidence of human habitation dating back 40,000 years.[4]
In Germany some experts found signs of cannibalism in the caves at the Hönne.
Caves are also important for geological research because they can reveal details of past climatic conditions in speleothems and sedimentary rock layers.
Caves are frequently used today as sites for recreation. Caving, for example, is the popular sport of cave exploration. For the less adventurous, a number of the world's prettier and more accessible caves have been converted into show caves, where artificial lighting, floors, and other aids allow the casual visitor to experience the cave with minimal inconvenience. Caves have also been used for BASE jumping and cave diving.
Caves are also used for the preservation or aging of wine and cheese. The constant, slightly chilly temperature and high humidity that most caves possess makes them ideal for such uses.
[edit] See also
Subterranean isle in Križna jama
Cave Conservancies
Cave Research Foundation
Caving
Flowstone
Grotto
List of caves
Mining
National Speleological Society
Pit Cave
Sinkhole
Speleology
Speleothem
Stalactite
Stalagmite
Wine caves
CAVING
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Caving frequently involves a lot of mud.
Caving is the recreational sport of exploring caves. In contrast, speleology is the scientific study of caves and the cave environment.[1]
Contents[hide]
1 Overview
2 Naming issues
3 Practice and equipment
4 Safety
5 Cave conservation
6 Caving organizations
7 See also
8 Popular culture
8.1 Documentaries
8.2 Feature (fictional) films
9 References
9.1 Footnotes
9.2 Notations
//
[edit] Overview
The challenges of the sport depend on the cave being visited, but often include the negotiation of pitches, squeezes, and water (though actual cave diving is a separate sub-specialty undertaken only by very few cavers). Climbing or crawling is often necessary, and ropes are used extensively for safety of the negotiation of particularly steep or slippery passages.
Caving is often undertaken for the enjoyment of the 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. Virgin cave systems comprise some of the last unexplored regions on Earth and much effort is put into trying to locate and enter them. In well-explored regions (such as most first-world countries), the most accessible caves have already been explored, and gaining access to new caves often requires digging or diving.
Caves have been explored out of necessity (for shelter from the elements or from enemies), out of curiosity or for mystical reasons for thousands of years. However, only in the last century or two has the activity developed into a sophisticated, athletic pastime. In recent decades caving has changed considerably due to the availability of modern protective wear and equipment. It has recently come to be known as an "extreme sport" by some (though not commonly considered as such by its practitioners, who may dislike the term for its perceived connotation of disregard for safety).
Many of the skills of caving can also be used in the nature activities of mine exploration and urban exploration.
[edit] Naming issues
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. This 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 term "spelunking" began to convey the idea of inexperienced cavers, using unreliable light sources and cotton clothing. In 1985, Steve Knutson (editor of American Caving Accidents) made the following distinction:
...Note that I use the term 'spelunker' to denote someone untrained and unknowledgeable in current exploration techniques, and 'caver' for those who are.
This sentiment is exemplified by bumper stickers and t-shirts displayed by many cavers: "Cavers rescue spelunkers".
Potholing refers to the act of exploring potholes, a word originating in the north of England for predominantly vertical caves. The term is often used as a synonym for caving, and outside the caving world there is a general impression that potholing is a more "extreme" version of caving.[citation needed]
[edit] Practice and equipment
Caver in an Alabama cave showing common caving wear: overalls and helmet-mounted lights.
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 lights are most common, with halogen lamps being standard and white LEDs as the new competing technology. Many cavers carry two or more sources of light - one as primary and 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 lamps systems are an older form of illumination, inspired by miner's equipment, and are still used by some cavers.[2]
The type of clothes worn underground varies according to 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 and/or polypropylene underwear, and an oversuit of hard-wearing (e.g., cordura) and/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 is used, to provide some abrasion protection whilst 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 the nature of the cave, gloves are sometimes worn to protect the hands against abrasion and/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 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 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 faeces out of the cave are carried.
During very long trips, it may be necessary to camp in the cave. This necessitates the caver carrying sleeping and cooking equipment.
[edit] Safety
A caver begins rope descent of a vertical shaft using an abseil rack.
Main article: Cave rescue
Caves can be dangerous places; hypothermia, falling, flooding, and physical exhaustion are the main risks. Rescuing people from underground 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 specialised 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 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.
The risks are minimised by a number of techniques:
Checking that there is no danger of flooding during the expedition. Rainwater funneled underground can flood a cave very quickly, trapping people in cut-off passages and drowning them. After falling, this is the most likely fatal accident in caving.[citation needed]
Using teams of several, preferably at least of four cavers. If an injury occurs, one caver stays with the injured person while the other two go out for help, providing assistance to each other on their way out.
Notifying people outside the cave as to the intended return time. After an appropriate delay without a return, these will then organise a search party (usually made up by other cavers trained in cave rescues, as even professional emergency personnel are unlikely to have the skills to effect a rescue in difficult conditions).
Use of helmet-mounted lights (hands-free) with extra batteries. American cavers recommend a minimum of three independent sources of light per person, but two lights is common practice amongst European cavers.[citation needed]
Sturdy clothing and footwear, as well as a helmet, are necessary to reduce the impact of abrasions, falls, and falling objects. Synthetic fibers and woolens, which dry quickly, shed water, and are warm when wet, are vastly preferred to cotton materials, which retain water and increase the risk of hypothermia. It is also helpful to have several layers of clothing, which can be shed (and stored in the pack) or added as needed. In watery cave passages, polypropylene thermal underwear or wetsuits may be required to avoid hypothermia.
Cave passages look different from different directions. In long or complex caves, even experienced cavers can become lost. To reduce the risk of becoming lost, it is necessary to memorise the appearance of key navigational points in the cave as they are passed by the exploring party. Each member of a cave party shares responsibility for being able to remember the route out of the cave. In some caves it may be acceptable to mark a small number of key junctions with small stacks or "cairns" of rocks, or to leave a non-permanent mark such as high-visibility flagging tape tied to a projection.
Vertical caving using ladders or SRT (Single Rope Technique) to avoid the need for climbing passages that are too difficult. SRT however is a complex skill and requires proper training before use underground and needs well-maintained equipment. Some drops that are abseiled down may be as deep as several hundred meters (for example Harwood Hole).
[edit] Cave conservation
A vertical cave in Alabama, USA
Many cave environments are very fragile. Many speleothems can be damaged by even the slightest touch and some by impacts as slight as a breath.
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, a particular species found in a cave may live within that cave alone, and be found nowhere else in the world. 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. Despite their often frightening reputation in fiction and in the movies, bats generally have more to fear from humans than vice-versa. Bats can be beneficial to humans in many ways, especially through their important ecological role in reducing insect pest populations, and pollination of plant species. Bats which hibernate are most vulnerable during 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 the warmer months when they are most sensitive and vulnerable.
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 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 the touch of any but the most careful archaeologist.
[edit] Caving organizations
Cavers in many countries have created organizations for the administration and oversight of caving activities within their nations. Among the oldest of these are the National Speleological Society (1941) of the USA (originally formed as the Speleological Society of the District of Columbia on May 6, 1939) and the Swiss Society of Speleology created in 1939 in Geneva, but the first 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. For a list of these organizations, see Caving organizations.
[edit] See also
Category:Caving by country
Cave
Cave rescue
Speleology, the scientific study of caves
Urban exploration, an activity similar to caving, but done in urban areas
Caving organizations
List of caves
Pit cave
[edit] Popular culture
[edit] Documentaries
Journey Into Amazing Caves (2001)
Caverns of the Mojave: An Expedition with Real Cavers (2006)
Planet Earth (2006), fourth episode "Caves"
[edit] Feature (fictional) films
The Cave (2005)
The Descent (2005)
The Cavern (2005)
[edit] References
[edit] Footnotes
^ Caving in New Zealand (from Te Ara Encyclopedia of New Zealand)
^ Caving equipment and culture (from Te Ara Encyclopedia of New Zealand)
From Wikipedia, the free encyclopedia
(Redirec
ted fro
m Caves) 
Jump to: navigation, search
Lechuguilla Cave, New Mexico
For other uses, see Cave (disambiguation).
A cave is a natural underground void large enough for a human to enter. Some people suggest that the term cave should only apply to cavities that have some part that does not receive daylight; however, in popular usage, the term includes sm
aller spaces like sea caves, rock shelters, and grottos.Speleology is
the science of exploration and study of all aspects of caves. Exploring a cave for recreation or science may be called caving, potholing, or occasionally (only in Canada and the United States), spelunking (see Caving).Contents[hide]
1 Types and formation
2 Patterns
3 Geographic distribution
4 Record lengths, depths, pitches and volumes
5 Ecology
6 Archaeological and social importance
7 See also
8 References
9 External links
//
[edit] Types and formation
The formation and development of caves is known as speleogenesis. Caves are formed by various geologic processes. These may involve a combination of chemical processes, erosion from water, tectonic forces, microorganisms, pressure, atmospheric influences, and even digging.
Most caves are formed in limestone by dissolution.
Speleothems in Hall of the Mountain King, Ogof Craig a Ffynnon, South Wales.
Solutional caves may form anywhere with rock that is soluble, and are most prevalent in limestone, but can also form in other material, including chalk, dolomite, marble, granite, salt, sandstone, fossilized coral and gypsum.
The largest and most abundant solutional caves are located in limestone. Limestone dissolves under the action of rainwater and groundwater charged with H2CO3 (carbonic acid) and naturally occurring organic acids. The dissolution process produces a distinctive landform known as karst, characterized by sinkholes, sinking streams, and underground drainage. Limestone caves are often adorned with calcium carbonate formations produced through slow precipitation. This include: flowstones, stalactites, stalagmites, helictites, draperies, soda straws and columns. These secondary mineral deposits in caves are called speleothems.
The world's most spectacularly decorated cave is generally regarded to be Lechuguilla Cave in New Mexico. Lechuguilla and nearby Carlsbad Caverns are now believed to be examples of another type of solutional cave. They were formed by H2S (hydrogen sulfide) gas rising from below, where reservoirs of oil give off sulfurous fumes. This gas mixes with ground water and forms H2SO4 (sulfuric acid). The acid then dissolves the limestone from below, rather than from above, by acidic water percolating from the surface.
Exploring a lava tube in Hawaii
Some caves are formed at the same time as the surrounding rock. These are sometimes called primary caves.
Lava tubes are formed through volcanic activity and are the most common 'primary' caves. The lava flows downhill and the surface cools and solidifies. The hotter lava continues to flow under that crust, and if most of the liquid lava beneath the crust flows out, a hollow tube remains, thus forming a cavity. Examples of such caves can be found on Tenerife, Big Island, and many other places. Kazumura Cave near Hilo is a remarkably long and deep lava tube; it is 65.6 kilometers (40.8 mi) long.
Blister caves are also formed through volcanic activity.
Painted Cave, a large sea cave, Santa Cruz Island, California
Sea caves are found along coasts around 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 meters (16 ft) to 50 meters (160 ft) in length but may exceed 300 meters (980 ft).
Glacier cave in Big Four Glacier, Big Four Mountain, Washington, ca. 1920.
Glacier caves occur in ice and under glaciers and are formed by melting. They are also influenced by the very slow flow of the ice, which tends to close the caves again. (These are sometimes called ice caves, though this term is properly reserved for 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.
Talus caves are the openings between rocks that have fallen down into a pile, often at the bases of cliffs.
Anchihaline 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 faunas.
[edit] Patterns
Branchwork caves resemble surface dentritic stream patterns; they are made up of passages that join downstream as tributaries. Branchwork caves are the most common of cave patterns and are formed near sinkholes where groundwater recharge occurs. Each passage or branch is fed by a separate recharge source and converges into other higher order branches downstream.[1]
Angular Network caves form from intersecting fissures of carbonate rock that have had fractures widened by chemical erosion. These fractures form high, narrow, straight passages that persist in widespread closed loops.[1]
Anastomotic caves largely resemble surface braided streams with their passages separating and then meeting further down drainage. They usually form along one bed or structure, and only rarely cross into upper or lower beds.[1]
Spongework caves are formed as solution cavities are joined by mixing of chemically diverse water. The cavities form a pattern that is three-dimensional and random, resembling a sponge.[1]
Ramiform caves form as irregular large rooms, galleries, and passages. These randomized three-dimensional rooms form from a rising water table that erodes the carbonate rock with hydrogen-sulfide enriched water.[1]
[edit] Geographic distribution
Caves are found throughout the world, but only a portion of them have been explored and documented by cavers. The distribution of documented cave systems is widely skewed toward 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 great generalization, as large expanses of North America and Asia contain no documented caves, whereas areas such as 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 kilometers (390,000 sq mi) - has relatively few documented caves.
[edit] Record lengths, depths, pitches and volumes
Canyon passage in Mammoth Cave, the world's longest cave.
The cave system with the greatest total length of passage is Mammoth Cave (Kentucky, USA) at 591 kilometers (367 mi) in length. This record is unlikely to be surpassed in the near future, as the next most extensive known cave is Jewel Cave near Custer, South Dakota, at 225 kilometers (140 mi).[2]
The deepest known cave (measured from its highest entrance to its lowest point) is Voronya Cave (Abkhazia, Georgia), with a depth of 2,191 meters (7,190 ft).[3] This was the first cave to be explored to a depth of more than 2 kilometers (1.2 mi). (The first cave to be descended below 1 kilometer (0.62 mi) was the famous Gouffre Berger in France). The Illyuzia-Mezhonnogo-Snezhnaya cave in Abkhazia, Georgia, (1,753 meters (5,750 ft)) and the Lamprechtsofen Vogelschacht Weg Schacht in Austria (1,632 meters (5,350 ft)) are the current second- and third-deepest caves. This particular record has changed several times in recent years.
The deepest individual pitch (vertical drop) within a cave is 603 meters (1,980 ft) in Vrtoglavica Cave in Slovenia, followed by Patkov Gušt at 553 meters (1,810 ft) in the Velebit mountain, Croatia.
The largest individual cavern ever discovered is the Sarawak chamber, in the Gunung Mulu National Park (Miri, Sarawak, Borneo, Malaysia), a sloping, boulder strewn chamber with an area of approximately 600 meters (2,000 ft) by 400 meters (1,300 ft) and a height of 80 meters (260 ft).
[edit] Ecology
Townsend's Big-eared bats in a cave
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 wholly in caves) and accidentals (animals not in one of the previous categories). Some authors use separate terminology for aquatic forms (e.g., stygobites, stygophiles, and stygoxenes).
Of these animals, the troglobites are perhaps the most unusual organisms. Troglobitic species often show a number of characteristics, termed troglomorphies, associated with their adaptation to subterranean life. These characteristics may include a loss of pigment (often resulting in 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, the Olm, and cave salamanders such as the Texas Blind Salamander.
Cave insects such as Oligaphorura (formerly Archaphorura) schoetti are troglophiles, reaching 1.7 millimeters (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 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 fragile nature of the cave ecosystem, 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, Liphistiidae 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 the lack of light and sustenance.
[edit] Archaeological and social importance
Taino petroglyphs in a cave in Puerto Rico
Throughout history, primitive peoples have made use of caves for shelter, burial, or as religious sites. Since items placed in caves are protected from the climate and scavenging animals, this means caves are an archaeological treasure house for learning about these people. Cave paintings are of particular interest. One example is the Great Cave of Niah, in Malaysia, which contains evidence of human habitation dating back 40,000 years.[4]
In Germany some experts found signs of cannibalism in the caves at the Hönne.
Caves are also important for geological research because they can reveal details of past climatic conditions in speleothems and sedimentary rock layers.
Caves are frequently used today as sites for recreation. Caving, for example, is the popular sport of cave exploration. For the less adventurous, a number of the world's prettier and more accessible caves have been converted into show caves, where artificial lighting, floors, and other aids allow the casual visitor to experience the cave with minimal inconvenience. Caves have also been used for BASE jumping and cave diving.
Caves are also used for the preservation or aging of wine and cheese. The constant, slightly chilly temperature and high humidity that most caves possess makes them ideal for such uses.
[edit] See also
Subterranean isle in Križna jama
Cave Conservancies
Cave Research Foundation
Caving
Flowstone
Grotto
List of caves
Mining
National Speleological Society
Pit Cave
Sinkhole
Speleology
Speleothem
Stalactite
Stalagmite
Wine caves
CAVING
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Caving frequently involves a lot of mud.
Caving is the recreational sport of exploring caves. In contrast, speleology is the scientific study of caves and the cave environment.[1]
Contents[hide]
1 Overview
2 Naming issues
3 Practice and equipment
4 Safety
5 Cave conservation
6 Caving organizations
7 See also
8 Popular culture
8.1 Documentaries
8.2 Feature (fictional) films
9 References
9.1 Footnotes
9.2 Notations
//
[edit] Overview
The challenges of the sport depend on the cave being visited, but often include the negotiation of pitches, squeezes, and water (though actual cave diving is a separate sub-specialty undertaken only by very few cavers). Climbing or crawling is often necessary, and ropes are used extensively for safety of the negotiation of particularly steep or slippery passages.
Caving is often undertaken for the enjoyment of the 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. Virgin cave systems comprise some of the last unexplored regions on Earth and much effort is put into trying to locate and enter them. In well-explored regions (such as most first-world countries), the most accessible caves have already been explored, and gaining access to new caves often requires digging or diving.
Caves have been explored out of necessity (for shelter from the elements or from enemies), out of curiosity or for mystical reasons for thousands of years. However, only in the last century or two has the activity developed into a sophisticated, athletic pastime. In recent decades caving has changed considerably due to the availability of modern protective wear and equipment. It has recently come to be known as an "extreme sport" by some (though not commonly considered as such by its practitioners, who may dislike the term for its perceived connotation of disregard for safety).
Many of the skills of caving can also be used in the nature activities of mine exploration and urban exploration.
[edit] Naming issues
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. This 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 term "spelunking" began to convey the idea of inexperienced cavers, using unreliable light sources and cotton clothing. In 1985, Steve Knutson (editor of American Caving Accidents) made the following distinction:
...Note that I use the term 'spelunker' to denote someone untrained and unknowledgeable in current exploration techniques, and 'caver' for those who are.
This sentiment is exemplified by bumper stickers and t-shirts displayed by many cavers: "Cavers rescue spelunkers".
Potholing refers to the act of exploring potholes, a word originating in the north of England for predominantly vertical caves. The term is often used as a synonym for caving, and outside the caving world there is a general impression that potholing is a more "extreme" version of caving.[citation needed]
[edit] Practice and equipment
Caver in an Alabama cave showing common caving wear: overalls and helmet-mounted lights.
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 lights are most common, with halogen lamps being standard and white LEDs as the new competing technology. Many cavers carry two or more sources of light - one as primary and 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 lamps systems are an older form of illumination, inspired by miner's equipment, and are still used by some cavers.[2]
The type of clothes worn underground varies according to 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 and/or polypropylene underwear, and an oversuit of hard-wearing (e.g., cordura) and/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 is used, to provide some abrasion protection whilst 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 the nature of the cave, gloves are sometimes worn to protect the hands against abrasion and/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 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 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 faeces out of the cave are carried.
During very long trips, it may be necessary to camp in the cave. This necessitates the caver carrying sleeping and cooking equipment.
[edit] Safety
A caver begins rope descent of a vertical shaft using an abseil rack.
Main article: Cave rescue
Caves can be dangerous places; hypothermia, falling, flooding, and physical exhaustion are the main risks. Rescuing people from underground 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 specialised 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 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.
The risks are minimised by a number of techniques:
Checking that there is no danger of flooding during the expedition. Rainwater funneled underground can flood a cave very quickly, trapping people in cut-off passages and drowning them. After falling, this is the most likely fatal accident in caving.[citation needed]
Using teams of several, preferably at least of four cavers. If an injury occurs, one caver stays with the injured person while the other two go out for help, providing assistance to each other on their way out.
Notifying people outside the cave as to the intended return time. After an appropriate delay without a return, these will then organise a search party (usually made up by other cavers trained in cave rescues, as even professional emergency personnel are unlikely to have the skills to effect a rescue in difficult conditions).
Use of helmet-mounted lights (hands-free) with extra batteries. American cavers recommend a minimum of three independent sources of light per person, but two lights is common practice amongst European cavers.[citation needed]
Sturdy clothing and footwear, as well as a helmet, are necessary to reduce the impact of abrasions, falls, and falling objects. Synthetic fibers and woolens, which dry quickly, shed water, and are warm when wet, are vastly preferred to cotton materials, which retain water and increase the risk of hypothermia. It is also helpful to have several layers of clothing, which can be shed (and stored in the pack) or added as needed. In watery cave passages, polypropylene thermal underwear or wetsuits may be required to avoid hypothermia.
Cave passages look different from different directions. In long or complex caves, even experienced cavers can become lost. To reduce the risk of becoming lost, it is necessary to memorise the appearance of key navigational points in the cave as they are passed by the exploring party. Each member of a cave party shares responsibility for being able to remember the route out of the cave. In some caves it may be acceptable to mark a small number of key junctions with small stacks or "cairns" of rocks, or to leave a non-permanent mark such as high-visibility flagging tape tied to a projection.
Vertical caving using ladders or SRT (Single Rope Technique) to avoid the need for climbing passages that are too difficult. SRT however is a complex skill and requires proper training before use underground and needs well-maintained equipment. Some drops that are abseiled down may be as deep as several hundred meters (for example Harwood Hole).
[edit] Cave conservation
A vertical cave in Alabama, USA
Many cave environments are very fragile. Many speleothems can be damaged by even the slightest touch and some by impacts as slight as a breath.
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, a particular species found in a cave may live within that cave alone, and be found nowhere else in the world. 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. Despite their often frightening reputation in fiction and in the movies, bats generally have more to fear from humans than vice-versa. Bats can be beneficial to humans in many ways, especially through their important ecological role in reducing insect pest populations, and pollination of plant species. Bats which hibernate are most vulnerable during 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 the warmer months when they are most sensitive and vulnerable.
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 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 the touch of any but the most careful archaeologist.
[edit] Caving organizations
Cavers in many countries have created organizations for the administration and oversight of caving activities within their nations. Among the oldest of these are the National Speleological Society (1941) of the USA (originally formed as the Speleological Society of the District of Columbia on May 6, 1939) and the Swiss Society of Speleology created in 1939 in Geneva, but the first 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. For a list of these organizations, see Caving organizations.
[edit] See also
Category:Caving by country
Cave
Cave rescue
Speleology, the scientific study of caves
Urban exploration, an activity similar to caving, but done in urban areas
Caving organizations
List of caves
Pit cave
[edit] Popular culture
[edit] Documentaries
Journey Into Amazing Caves (2001)
Caverns of the Mojave: An Expedition with Real Cavers (2006)
Planet Earth (2006), fourth episode "Caves"
[edit] Feature (fictional) films
The Cave (2005)
The Descent (2005)
The Cavern (2005)
[edit] References
[edit] Footnotes
^ Caving in New Zealand (from Te Ara Encyclopedia of New Zealand)
^ Caving equipment and culture (from Te Ara Encyclopedia of New Zealand)
Minggu, 31 Agustus 2008
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Julio Iglesias - The Most Beautiful Girl Lyrics
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Julio Iglesias - The Most Beautiful Girl Lyrics
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J.R.Sean Kingston - Beautiful Girl
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The ADSL Ethernet & USB Combo Modem is the perfect high-speed WAN bridge/Modem. This full-featured product is specifically designed to connect to the Internet. For game users, the ADSL Modem had already pre configured for several low latency game ports. Just click on the game you are playing on line and the rest is done for you The ADSL Modem is fully compatible with all PCs; as long as the PC supports an Ethernet interface and is running a TCP/IP protocol stack, your PC can have high-speed WAN access. So, plug in the ADSL Modem (refer to easy start guide), configure it (per your ISP’s requirements) and enjoy the fast Internet access like never before.Ports and ButtonsReset and Restore to Factory Defaults: The restore to factory defaults feature will set the ADSL Modem to its factory default configuration by resetting the ADSL Modem. You may need to place the ADSL Modem into its factory defaults if the configuration is changed, you loose the ability to interface to the ADSL Modem via the web interface, or following a software upgrade,. To reset the ADSL Modem, simply press the reset button for about 10 seconds. The ADSL Modem will be reset to its factory defaults and after about 30 40 seconds the ADSL
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AG241
Product Information
(customer reviews)
ADSL 2+ Gateway with 4 Port Switch
Bhinneka Part No
:
SKU00408394
Shipping Weight (Tarif)
:
2 kg
Price
:
US$ 75.00
Cicilan
:
6 x Rp 115,750
Overview
The All-In-One Solution for Internet Connectivity in Your Home
Detail Specifications
O/S
Internet Explorer 5.0 or Netscape Navigator 6 or Higher for Web-based Configuration
Feature
High-speed ADSL Modem gives you a fast, "Always On" connection to the Internet.
Connect your PCs via the built-in Router and 4-port Switch to jump start your Ethernet network and share the Internet throughout your household.
Advanced firewall and security features protect your PCs, your data, and your family.
Compatible with both ADSL1 or ADSL2 standards
Power
12VDC 1A
Standard
IEEE 802.3u, IEEE 802.3, ITU G.992.1 (g.dmt),
Port
Power, Line, Ethernet (1-4)
LED
Power, Ethernet (1-4), DSL, Internet ITU G.992.2 (g.lite), ITU G.992.3, ITU G.992.5, ANSI T1.413i2
Dimension (WxDxH)
186 x 154 x 48 mm
AZTECH
Aztech ADSL 2/2+ Ready Ethernet USB Combo Bridge/Router (DSL 600EU)
The Aztech DSL600EU ADSL Ethernet USB Combo Bridge/Router Modem uses Texas Instruments AR7 Chipset solution that fully complies to ANSI T1.413 Issue 2, ITU-T G.992.1 (G.dmt) and G.992.2 (G.lite) ADSL standard. Aztech DSL600EU also provides future proof functionality with higher data transmission rates with ADSL2, ADSL2+, Extended Reach-ADSL support.
Targeted at the residential users, it is for both the single user with Bridge mode with host based PPPoE Client or for multi-users utilizing the DSL600EU inbuilt PPPoE/A, IP routing, NAT functionality to share the ADSL link.
It comes with Stateful Packet Inspection firewall and DMZ support for a full security options against malicious hackers.
PRODUCT SPECIFICATIONS
ADSL/ATM Support
ANSI T1.413 issue 2, ITU-T G.992.1 (G.dmt) and G.992.2 (G.lite) compliant
ADSL2, ADSL2+, RE-ADSL compliant
Rate Adaptive modem at 32 Kbps steps
Dynamic Adaptive Equalisation to improve Carrier's service area
Bridge Tap Mitigation support
ATM Layer with Traffic shaping QoS Support (UBR, CBR, VBR-rt, VBR-nrt)
AAL ATM Attributes - AAL5
Multiple PVC up to 8 support (Bridge Support)
Spectral compatibility with POTS
F5 OAM Loopback/Send and Receive
Encapsulation Support
RFC2684 Bridge and Routed LLC and VC Mux support
RFC2364 PPPoA Client support
RFC2516 PPPoE Client support
RFC2225/RFC1577 Classical IP Support
Transparent Bridge Support
PAP/CHAP/MS-CHAP for Password Authentication Support
Network Support
Static IP, Dynamic RIP routing support
IP/TCP/UDP/ICMP/ARP/RARP Application Support
Network Address Translation (NAT)
Port Mapping/Forwarding
Easy setup of Port Forwarding rules for popular Games/Application
NAT Application Level Gateway for popular applications
DHCP Server/Relay/client
DNS Relay Agent
DMZ support
Single Session IP Sec and PPTP/L2TP VPN pass through support
PPP Always on with configurable timeout
PPP Dial on Demand
Management Support
Web Based HTTP management GUI
TFTP/FTP Support for Firmware Upgrade
Web Based Firmware Upgrade (Local)
Soft Factory Reset Button via Web GUI
Diagnostic Test (DSL, OAM, Network, Ping Test)
Telnet/CLI (Read Only)
Syslog Support
Firmware upgrade-able for future feature enhancement
Security Support
NAT for basic Firewall support
Packet Filtering Firewall Support
Stateful Packet Inspection Support
Protection against Denial of Service attacks
Password Authentication to Modem
Hardware
Texas Instrument TNETD7300 Single Chip Network Processor/AFE/Line Driver Chipset
2 MB Flash ROM
8 MB SDRAM
Dying Gasp Support
ITU K.21 Support
Platform support
For Ethernet :- OS Independent
For USB : - Windows 98SE - Windows ME - Windows 2000 - Windows XP - Windows 2003
Power Requirements
Input Voltage : 9V DC +/- 10%
Input Current : 1A
Physical Specifications
1 x PPP LED
1 x Power LED
1 x DSL Link Status LED
1 x Ethernet Link/Activity Status LED
1 x USB Status LED
External Connectors
1 x RJ-11 Telephone socket for ADSL line
1 x RJ45 for 10/100Base-T Ethernet (MDI-X)
1 x USB 1.1 Type B
1 x DC Jack for Power Input
1 x Factory Default Reset Button
Measurements
Dimension : 144 (L) x 109 (W) x 30 (H) mm
Weight : Approx. 250g
Overview
The 3Com® OfficeConnect® ADSL Wireless 54 Mbps 11g Firewall Router combines an ADSL2/2+ modem, router, 802.11g wireless access point, four-port switch, and firewall to enable up to 253 total (64 wireless) users to economically and securely share a share a single ADSL or ADSL2/2+ connection. The high-speed routing engine and 54 Mbps wireless throughput easily handle large data transfers and Internet downloads, including those from multimedia applications.
Detail Specifications
Feature
All-in-one device includes an ADSL2/2+ modem, 802.11g access point, router, firewall, and four-port switch in one box
Easy, cost-effective Internet sharing for up to 253 (64 wireless) simultaneous users
SurfControl Web Filter, subscription based web filtering; 14-day free trial is included
128-bit WPA/WPA2 with TKIP/AES encryption, 40/64 and 128-bit Wired Equivilant Privacy (WEP)
Encryption for legacy wireless help keep wireless transmissions private
Support of WDS (wireless distribution system) makes setup of an extended or completely wireless network very simple (requires wireless access points that support WDS)
Additional security features include URL or keyword filtering to control access to inappropriate web sites, allow/deny access control lists, SSID Broadcast Disable, IP and MAC filtering
Stateful packet inspection and hacker pattern detection firewall features help protect your network from hackers and intrusions
VPN pass-through permits secure connections to remote offices
Four 10/100 Ethernet LAN ports with Auto MDI/MDIX provide wired LAN connectivity to multiple users or another LAN
IP routing (static, RIP v1 and 2) enables the router to be used in multi-networked environments
Set-up wizards and an intuitive web browser interface makes set-up and configuration easy
Port
LAN ports: 4 autosensing RJ-45 10BASE-T/100BASE-TX
WAN : 1 RJ-11 port
The 3Com® OfficeConnect® ADSL Wireless 54 Mbps 11g Firewall Router combines an ADSL2/2+ modem, router, 802.11g wireless access point, four-port switch, and firewall to enable up to 253 total (64 wireless) users to economically and securely share a share a single ADSL or ADSL2/2+ connection. The high-speed routing engine and 54 Mbps wireless throughput easily handle large data transfers and Internet downloads, including those from multimedia applications.
Detail Specifications
Feature
All-in-one device includes an ADSL2/2+ modem, 802.11g access point, router, firewall, and four-port switch in one box
Easy, cost-effective Internet sharing for up to 253 (64 wireless) simultaneous users
SurfControl Web Filter, subscription based web filtering; 14-day free trial is included
128-bit WPA/WPA2 with TKIP/AES encryption, 40/64 and 128-bit Wired Equivilant Privacy (WEP)
Encryption for legacy wireless help keep wireless transmissions private
Support of WDS (wireless distribution system) makes setup of an extended or completely wireless network very simple (requires wireless access points that support WDS)
Additional security features include URL or keyword filtering to control access to inappropriate web sites, allow/deny access control lists, SSID Broadcast Disable, IP and MAC filtering
Stateful packet inspection and hacker pattern detection firewall features help protect your network from hackers and intrusions
VPN pass-through permits secure connections to remote offices
Four 10/100 Ethernet LAN ports with Auto MDI/MDIX provide wired LAN connectivity to multiple users or another LAN
IP routing (static, RIP v1 and 2) enables the router to be used in multi-networked environments
Set-up wizards and an intuitive web browser interface makes set-up and configuration easy
Port
LAN ports: 4 autosensing RJ-45 10BASE-T/100BASE-TX
WAN : 1 RJ-11 port
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