Speleology

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Grotte des Faux-Monnayeurs, Switzerland

Speleology is the scientific study of caves and other karst features, their make-up, structure, physical properties, history, life forms, and the processes by which they form (speleogenesis) and change over time (speleomorphology). The term speleology is also sometimes applied to the recreational activity of exploring caves, but this is more properly known as caving, spelunking or potholing.

Speleology is a cross-disciplinary field that combines the knowledge of chemistry, biology, geology, meteorology and cartography to develop portraits of caves as complex, evolving systems.

1 History
2 Cave geology and hydrology
- 2.1 Geochemistry speleothems
3 Cave cartography
- 3.1 Survey software issues
4 Cave biology
5 Other areas of cave science
6 References
7 External links

[edit] History

Prior to the mid-ninteenth century the scientific value of caves was considered only in its contribution to other branches of science, and cave studies were considered part of the larger disciplines of geography, geology or archaeology. Very little cave-specific study was undertaken prior to the work of Édouard-Alfred Martel (1859 - 1938), the 'father of modern speleology', who through his extensive and well-publicised cave explorations introduced the concept of speleology as a distinct area of study. In 1895 Martel founded the Société de Spéléologie, the first organization devoted to cave science in the world.

The growth of speleology is directly linked with that of the sport of caving, both because of the stimulation of public interest and awareness, and the fact that most speleological field-work has been conducted by sport cavers.

[edit] Cave geology and hydrology

See karst

[edit] Geochemistry speleothems

See speleothem

[edit] Cave cartography

The creation of an accurate, detailed map is one of the most common technical activities undertaken within a cave. Cave maps, called surveys, can be used to compare caves to each other by length, depth and volume, may reveal clues on speleogenesis, provide a spatial reference for further scientific study, and assist visitors with route-finding.

A survey team begins at a fixed point (such as the cave entrance) and measures a series of consecutive line-of-sight measurements between stations. These measurements include direction (azimuth) taken with a compass, inclination from horizontal (dip) taken with a clinometer, and distance measured with a low-stretch tape. Coincident with recording straight-line data, details of passage dimensions, shape, gradual or sudden changes in elevation, the presence or absence of still or flowing water, and material on the floor are recorded. Later, the cartographer presents the technical measurements as a line-plot, then draws details around the line-plot for a completed cave survey. Cave surveys drawn on paper are often presented in two-dimensional plan or profile views, while computer surveys may simulate three dimensions. Although primarily designed to be functional, some cavers consider cave surveys as an art form.

The accuracy, or grade, of a cave survey is dependent on the methodology of measurement. A common survey grading system is that created by the British Cave Research Association in the 1960s, which ranges from Grade One (a simple sketch based on memory) to Grade Six (use of tripod-mounted instruments and a temperature-calibrated steel tape), with the most common grade being Five. A BCRA Grade 5 survey utilizes handheld instruments taking measurements within one degree accuracy or better and a tape measure accurate to ten centimeters or better, per station.

The equipment used to undertake a cave survey continues to improve. The use of computers, inertia systems, and electronic distance finders has been proposed, but no practical underground applications have evolved at present.

[edit] Survey software issues

Surveying based on a centreline constructed from a chain of measurements down the passages of a cave are subject to loop closure errors when a round trip or a second entrance is surveyed to and there is a discrepancy. Surveying software is widely used by surveyors to redistribute the closure errors throughout the cave centreline in order to improve its consistency.

The fact that this centreline can alter in shape over the years as a cave is explored and more loops and entrances are discovered presents a difficult challenge to the drawing up of maps of passages and chambers based on these centrelines. Paper-only surveys either had to be redrawn from scratch every few years, or fudged, or limited in scope to one section of a cave which is complete and likely to remain static although subject to repositioning.

[edit] Cave biology

Caves provide a home for many unique biota. Cave ecologies are very diverse, and not sharply distinct from surface habitats. Generally however, the deeper the cave becomes, the more rarefied the ecology.

Cave environments fall into three general categories:

Endogean: the parts of caves that are in communication with surface soils through cracks and rock seams, groundwater seepage, and root protrusion.

Parahypogean: the threshold regions regions near cave mouths that extend to the last penetration of sunlight.

Hypogean: or "true" cave environments. These can be in regular contact with the surface via wind and underground rivers, or the migration of animals, or can be almost entirely isolated. Deep hypogean environments can host autonomous ecologies whose primary source of energy is not sunlight, but chemical energy liberated from limestone and other minerals by chemoautotrophic bacteria.

Cave organisms fall into three basic classes:

Troglobites ("cave dwellers") are obligatory cavernicoles, specialized for cave life. Some can leave caves for short periods, and may complete parts of their life cycles above ground, but cannot live their entire lives outside of a cave environment. Examples include chemotrophic bacteria, some species of flatworms, collembola, and Blindfish.

Troglophiles ("cave lovers") can live part or all of their lives in caves, but can also complete a life cycle in appropriate environments on the surface. Examples include cave crickets, millipedes, pseudoscorpions and spiders.

Trogloxenes ("cave guests"): Frequents caves, and may require caves for a portion of its life cycle, but must return to the surface (or a parahypogean zone) for at least some portion of its life. Hibernating reptiles and mammals are the most widely recognized examples.

There are also so-called accidental trogloxenes which are surface organisms that enter caves for no survival reason. Some may even be troglophobes (“cave haters”), which cannot survive in caves for any extended period. Examples include deer which fell through a sinkhole, frogs swept into a cave by a flash flood, etc.

The two factors that limit cave ecologies are generally energy and nutrients. To some degree moisture is always available in actively-forming Karst caves. Cut off from the sunlight and steady deposition of plant detritus, caves are poor habitats in comparison with wet areas on the surface. The majority of energy in cave environments comes from the surplus of the ecosystems outside. One major source of energy and nutrients in caves is dung from trogloxenes, the majority of which is deposited by bats. Other sources are mentioned above. ^[1]

Cave ecosystems are very fragile. Because of their rarity and position in the ecosystem they are threatened by a large number of human activities. Dam construction, limestone quarrying, water pollution and logging are just some of the disasters that can devastate or destroy underground biological communities. ^[2]

[edit] Other areas of cave science

Speleologists also work with archaeologists in studying underground ruins, tunnels, sewers and aquaducts, such as the various inlets and outlets of the Cloaca Maxima in Rome.[1]