cave

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The brilliant stalagmite in the Postojna Caves , Slovenia (2007)

A cave is a naturally formed underground cavity that is large enough to be entered by humans and is longer than five meters. This definition of the term in caving ( speleology ) differs from the colloquial use.

definition

Caves in the sense of this article are exclusively naturally formed cavities. Caves are created through geological processes.

Accordingly, cavities such. B. mines , earth stables , rock tombs , hypogea , catacombs , air raid tunnels , basement or artificial caves no caves. Lately the term Subterranea has been used for this (derived from the Latin word for “underground”), but so far mainly in English.

Types of caves

Primary cave with root threads in lava rock in Hawaii
Outcrop with a small secondary cave in the Swabian Muschelkalk

Primary caves

Primary caves are caves that were created at the same time as the rock surrounding them.

Numerous small primary cavities were created if the cavities were left out during the sedimentation during the formation of carbonate sediments (e.g. in the formation of tufa limestone ) , or if they were formed before processes of cementation or diagenesis began.

Lava caves are also common . Often there are smaller cavities that were created by gas bubbles in solidifying lava. Most of the time, these cavities are only opened by accident. But there are also lava caves many kilometers long. These so-called lava tubes are lava channels whose surface has cooled and solidified, while the liquid lava continued to flow underneath until the eruption came to a standstill. Such caves can be found in Hawaii , Iceland and the Canary Islands .

Secondary caves

Secondary caves are caves that were formed later than the rock surrounding them.

This category includes caves that have been created by corrosion (chemical weathering), erosion (mechanical weathering), tectonics (movements of the earth's crust or rock layers) or a combination of these influences.

Secondary caves are found in rocks that are water-soluble in the broadest sense, especially in the various types of limestone . Rainwater contains carbon dioxide , which it can dissolve depending on its temperature. Colder water can dissolve more carbon dioxide. Depending on the carbon dioxide concentration in the water, carbonic acid weathering of the lime occurs. By capillary action , the water penetrates into fine cracks in the rock and dissolves lime. That alone does not explain any significant cave formation. However, since the ability of water to dissolve lime does not run linearly with the carbon dioxide concentration, so-called mixed corrosion occurs : If two different solutions saturated with lime meet in the mountain and these mix, a new concentration of carbon dioxide is created, which is an additional Can dissolve lime. This can create a larger cavity at this point. This is the key to cave formation, so to speak.

Phreatic and vadose caves

The Silberloch in Pleigne in the Swiss Jura : in the front part a flooded former mine (picture), in the back part an active water cave

The erosive (mechanical) forces of the water continue to appear in a formative manner, both in the secondary caves, which are primarily formed by dissolution processes, and in the primary caves ; one then speaks of active water caves . If the cavity is sufficient so that large amounts of water can flow through, it is possible that the water will carry away fragments of rock broken from the ceiling and thus significantly change the cave space. In the course of time, water penetrates deeper and deeper areas of the mountain and the previously flowed through become more or less anhydrous.

During this educational process one can distinguish:

  • Phreatic caves : These are completely filled with water, e.g. B. Spring caves.
  • Active vadose caves : These are still regularly traversed by water, the cave formation in these parts is not yet complete.
  • Inactive vadose caves : These are dry, here the cave formation is complete.

In large cave systems, those with considerable height differences, one can find all three appearances. The deepest parts are often completely under water, the middle floors are traversed by water and the highest are dry. This is also where the cave begins to slowly decay: parts of the ceiling can collapse. If this happens just below the surface of the earth, this can be recognized by means of sinkholes (collapse funnels) (see also: Cenote ).

Caves created at joints

The cleft joint cave is also called a cleft cave or crevice cave . It is a tectonically created cave along fissures , which was created by corrosion in karstification-capable rocks (e.g. dolomite ) along a fissure.

A fracture joint cavity is a cavity located on fracture joints. A layer joint cavity was created at layer joints.

Half-cave

Half caves are also called balms . Most of them are outbreaks in rock faces that are only caused by erosion. The main feature of these caves is that their depth is less than the width of the portal and they do not have a lightless cave part. From a great distance, such half-caves often look like portals of normal caves. Half-caves were occasionally used as dwelling caves in earlier times ( abri ), until more recently also by hunters or poachers.

Other types of caves

The Ogof Craig A Ffynnon cave
in Wales

Many caves have several names depending on how you look at them.

Designation according to the origin

  • Weathering cave : also known as the eruption cave, created by mechanical processes such as frost blasting or rainwater washout
  • Bladder cavity : created by gas inclusion in lava
  • Surf cave : created by surf
  • Erosion cave : secondary cave created by erosion
  • Incasion Cave : created by a crime
  • Corrosion cave : created by corrosion
  • Leach cave : created by dissolving the rock without chemical conversion (e.g. salt cave )
  • Tectonic cave : created by tectonic forces
  • Fall cave : created by falling fall
  • Wind cave or Aeolian cave : created by wind erosion

Designation according to the shape

  • Passage cave: cave with several entrances that are not next to each other
  • Horizontal cave : predominantly horizontal duct system
  • Shaft cave : predominantly vertical corridor system (see shaft )

Name after the rock

Caves in special environments

  • Ice cave : Cave in which essential parts (especially parts close to the entrance) are frozen (usually high alpine caves)
  • Glacier cave: Cave in a glacier, created by crevices and meltwater
  • Lava cave : cave of volcanic origin
  • Covered cave: cave under or between boulders
  • Bank cave: secondary cave on a surface water, created by erosion

Other names

Cave system

overall length completely or
almost
 unbranched 		 reticulated or branched
like a labyrinth
less than 50 m Small cave Small cave system
50 m to 500 m Middle cavity Middle cave system
500 m to 5000 m  Large cave Large cave system
over 5000 m Giant cave Giant cave system 

One speaks of a cave system in connection with longer caves in which one can distinguish a main passage and a few side passages.

If it is possible to prove a connection between two neighboring systems, the name of the previously larger system is usually adopted for the entire system. One example is the Sac Actun underwater cave system in Yucatán . At the time of unification in 2007, Sac Actun was 14.3 km longer than the neighboring Nohoch Nah Chich system . The official name is therefore Sistema Sac Actun (with 222.7 km the second longest underwater system).

If you connect several caves by artificial connecting passages, a cave system is also created. In this case, the names of the caves are mostly retained. The name for the entire system is then, for example, “Bergerhöhlen-Platteneckeishöhlen-Bierloch-System”. This system consists of three originally separate caves in the Tennengebirge in Salzburg.

Records

The following data may not be current. One of the reasons for this is that it often takes longer for research results to be published. Since caving is almost exclusively done by people as a hobby in their free time, the evaluation and documentation of the data obtained often takes longer. It is customary to publish data only after a conscientious survey of the discovered caves or cave parts has been carried out. The spaces traveled are not always measured immediately.

The mentioned records should also not be understood in a sporting sense. Exploring a very long cave, provided it has a larger number of entrances, can be much easier than exploring a cave that is much shorter but only has a single access point. The exploration of deep shafts has also been simplified since the introduction of the single-rope technique , at least from above. On the other hand, ascending a cave from below still places extremely high demands on the performance of the researchers and the amount of material required.

In the ice palace of the Grünbergalm ice cave, Ebensee ( Salzkammergut , Austria )

World records

Europe

Germany

  • Longest cave: Giant thing shaft cave in Untersberg in the Berchtesgaden Alps in Bavaria, 21.3 km
  • Deepest cave: giant thing shaft cave, 1149 m

Austria

  • Longest cave: Schönberg cave system in the Dead Mountains in Upper Austria and Styria, 147 km (currently the longest cave in the EU)
  • Deepest cave: Lamprechtsofen in the Leoganger Steinberge in Salzburg, 1632 m, total length 51 km. For many years, until its upper entrance was discovered, the Lamprechtsofen was considered the “highest cave in the world”. Its lower entrance is almost the deepest point of the cave.

Switzerland

Use and exploration

Caves were sometimes used for the permanent residence of people, e.g. B. as a dwelling ( dwelling cave ). Corresponding traces were found in the Stefánshellir in Iceland. In southern Europe and other warmer countries there were and are people who live in artificial caves, for example in Greece (e.g. Meteora monastery ).

Natural caves were also visited by ancient people who used them as places of worship and, if necessary, designed them as such ( cave paintings , petroglyphs ). Caves are the frequent sites for well-preserved cave finds from the Stone Age and are therefore of great importance for archaeological research. Entire cave groups were grouped together in this sense, such as the caves of the oldest Ice Age art on the Swabian Alb . A current example of an archaeologically actively researched cave is the leaf cave in Hagen. Cave finds also serve to research fauna and flora as well as a climate archive , in which, in addition to stalactites , duct shapes and sediment deposits can provide information about climate development.

Today the tourist use in the form of show caves is also important. Even the stretched and intermittent illumination with artificial light allows vegetation with chlorophyll, such as the mosses that spread through fine spores, to germinate , starting at the points of high illuminance , visible in the green.

The use as a quarry is less desirable , especially for the purpose of mining stalactites for sale to stone collectors or for making jewelry. In large areas of the Third World, caves that are often still unknown to science have been completely emptied. Another breakdown product from caves is bat guano .

The use of caves for caving is controversial .

The exploration of caves is known as cave exploration or speleology . It is usually done by volunteer speleologists who collect their results in cave cadastres .

In all forms of use, there are considerable conflicts between economic use and the interests of cave protection .

Cave as a motif

Caves often appear as a motif in myths , dreams or fairy tales . According to the analytical psychology in the tradition of Carl Gustav Jung , this is a special form of the mother archetype .

Movies

Periodicals

See also

literature

Web links

Wiktionary: cave  - explanations of meanings, word origins, synonyms, translations
Commons : cave  album with pictures, videos and audio files
Wikisource: Cave  - Sources and Full Texts

Individual evidence

  1. ↑ Lukas Plan: Speleology - Speleology. (PDF) Association of Austrian Speleologists, October 2007, p. C1 , accessed on October 17, 2016 .
  2. ↑ Jochen Duckeck: Speleology. December 27, 2011, accessed February 18, 2012 .
  3. ^ Walter Gallmann: Caves & Cave Creation. (PDF; 536 kB) Swiss Cave Diving Instructors, October 12, 2006, accessed on February 18, 2012 .
  4. ↑ a b Long underwater caves in Quintana Roo Mexico. NSS, Quintana Roo Speleological Survey (QRSS) , June 1, 2014, accessed June 19, 2014 .
  5. ^ Bob Gulden: Worlds longest caves. In: GEO2 Committee on long and deep caves. National Speleological Society (NSS), June 16, 2014, accessed June 19, 2014 .
  6. ↑ Новини Печера Оптимістична. 2017, Retrieved September 25, 2018 (Russian).
  7. ↑ KAZUMURA ​​CAVE TOURS. Retrieved September 25, 2018 .
  8. ↑ Researchers find the longest salt cave in the world. March 28, 2019, accessed March 29, 2019 .
  9. ↑ Верёвкина. May 4, 2018, Retrieved September 25, 2018 (Russian).
  10. ^ Bob Gulden: The Worlds Great Vertical Pits. In: GEO2 Committee on long and deep caves. NSS, March 17, 2012, accessed July 11, 2012 .
  11. ^ Bob Gulden: The Largest Underground Chambers by Surface Area. In: GEO2 Committee on long and deep caves. NSS, June 4, 2010, accessed February 18, 2012 .
  12. ↑ a b giant thing-Untersberg shaft cave. Working group for cave research Bad Cannstatt eV, October 2018, accessed on February 10, 2019 .
  13. ↑ Schönberg cave system. State Association for Speleology in Upper Austria, June 2018, accessed on September 25, 2018 .
  14. ↑ a b Bob Gulden: Worlds deepest caves. In: GEO2 Committee on long and deep caves. NSS, June 16, 2014, accessed June 19, 2014 .
  15. ^ Longest and deepest caves of Switzerland. Swiss caves with a length of more than 1000 meters. Swiss Speleological Society, September 21, 2012, accessed November 28, 2016 .