Natural caves

Different types of caves
Shafts are downward-leading vertical conduits from 10 to 200 m long which are linked by meanders (serpentine-shaped, high, narrow conduits). The entrance of a Ponor Cave is where a stream is swallowed up by the ground, whose visit is often thereby made dangerous. Caves are sometimes active, i.e. occasionally active. Fossil caves are now dry. These are often located high up, above adjacent valleys. Ice caves contain permanent underground glaciers. These are found in the Alps, but also in the Jura above 1000 m altitude. Siphons are caves which lie under water. Their study requires special technical equipment (cave scuba diving). Extensive cave systems are made up of the various types of caves described above.

Speleology
The natural caves in Switzerland are explored, mapped and documented by speleologists from the Swiss Society for Speleology (SSS). Each section of the SSS explores an area defined according to geological criteria. First, all cave entrances are sought, whether large or small. When an unknown entrance is discovered, the exploration begins with the necessary specialised equipment. The measurement and mapping of the cave are carried out together. Descriptive texts add detail to the observations. In many cases, the caves are short (less than 50 m) and the documentation can be prepared in one day. Sometimes the cave system is explored for several kilometres. The difficulties in advancing, as well as the work of documentation, limit the study to about 100 to 200 meters per day, without mentioning especially difficult days when only 10-20 m are able to be penetrated. The study of extensive cave systems, as for example the Hölloch (SZ, 207 km) or the Siebenhengste (BE, 160 km), require enormous amounts of work. In Switzerland, several dozens of new caves and 10 to 20 kilometres of unknown caves are discovered annually. Sometimes paleontological or archeological artefacts as well as sediments are found which yield important information concerning the past evolution of our landscape and climate.