Lac Pavin

Maar lake

The Lac Pavin is a volcanic crater lake in the Massif Central in the south-eastern edge of the Monts Dore. With an age of about 6000 years, the maar is one of the youngest volcanic objects in the Auvergne.

Location and size

The lake is 1197 m high in the Auvergne in the Puy -de- Dôme between the towns of Besse -en- Chandesse and the ski resort of Super Besse. He is about 44 ha in size and 90 m deep.

Meromiktischer lake

The Lac Pavin in France is unique in its water circulation: It runs meromictic. The mixture of water comprises a half-yearly and annual cycle, only the first 60 meters. The water at the bottom of the lake, 60-92 meters, is held there and give of gases such as carbon dioxide saturated, methane and hydrogen sulfide, which result from the decomposition of organic material and the water a foul smelling odor. The gas content makes monitoring of the lake is necessary since an increase in an abrupt and dangerous discharge can lead. According to scientists, the water has reached but no saturation and is located in a low-risk stable condition. Nevertheless, earth moving or seismic can disturb this balance and trigger a sudden degassing by the release of the contained in the underlying sediment gas.

The lake is home to lake trout, which on deep water (30 to 70 meters ) has adapted. Furthermore, living methanogenic bacteria in Lac Pavin, and other species which feed on this gas.

Legend

According to legend, every stone thrown into it triggers a storm.