tarnes

Tarnes are small mountain lakes or pools that form in basins carved by glacial erosion, typically in cirques or corries high in the mountains. The word tarn is used in English to describe this specific type of lake, and tarnes is the common plural form. The name is derived from historic usage in northern and alpine regions, reflecting the glacial origins of these waterways.

Formation and characteristics

Tarnes form when a glacier carves out a bowl-shaped depression in bedrock. As the glacier recedes, meltwater accumulates in the hollow, creating a lake. Tarnes are usually fed by snowmelt, rain, and groundwater, and they often have cold, clear, and nutrient-poor water. They tend to be smaller and deeper than many lowland lakes, with little sediment accumulation and limited aquatic productivity, though some are deep enough to sustain cold-water organisms.

Distribution

Tarnes occur worldwide wherever glaciation has occurred, including the Alps, Pyrenees, Carpathians, Himalayas, Andes, Rockies, and the mountains of Scotland and the Lake District in England. They are commonly found in remote, rugged terrain and are frequent subjects in mountaineering guides and landscape photography.

Ecology and use

Because of their isolation and harsh conditions, tarnes generally host sparse vegetation around their margins and support limited aquatic life. Some tarns may contain trout or other cold-water species, but many have no fish. Tarnes are valued for their scenic beauty and are popular destinations for hikers and outdoor recreation. They also provide natural archives for studying past climate, as sediments can preserve records of historical environmental change.

In summary, tarnes are characteristic mountain lakes formed by glacial sculpting, notable for their small size, clear waters, and alpine settings.