Glacier edge lake

Tasman Lake on the Tasman Glacier did not form until the mid-1970s

A glacier edge lake or glacier end lake is a body of stagnant water formed in the area of ​​the ground or terminal moraine of a glacier .

Emergence

A hollow shape is carved out by the flowing ice of the glacier tongue . The end and side moraines form a natural dam. The bottom and the terminal moraine are sealed by fine sediments in such a way that the meltwater from the glacier collects in this basin and can form a lake after the glacier tongue retreats . Today such lakes are mostly fed by rainwater and groundwater, in the Alps they continue to be fed by meltwater from the higher-lying areas. Most of the lakes at the edge of the glacier were formed after the end of the Ice Age, but they also appear after today's glaciers have melted.

Zungenbeckensee / Fjordsee

Zungenbeckensee within a glacial series (valley-side end)

A special post-glacial resulting lake form is the Zungenbeckensee . Basins deepened by ice-age glacier tongues , so-called tongue basins, exist in all regions that were ice-covered before times. Whether the lakes created in them are specifically designated as fjord lakes depends on the direction of movement of the ice forming the basin. Where the ice pushed down through mountain valleys, like when the fjords formed , they are called fjord lakes. Where the ice came from the ice sheet of a sea - in Europe the Baltic Sea -, corresponding to the formation of the fjords , one does not speak of a fjord sea . Such lakes can be found in northern Germany and other regions south and east of the Baltic Sea.

Examples

Glacier edge lake of the Trift glacier with glacier gate (mountain side end)

Glacier lakes are often found in Northern Brandenburg, the Alpine foothills and in inner-Alpine basins :

• Glacier edge lakes, but no fjord lakes:
  • Ammersee (?)
  • Federsee
  • Grimnitzsee
  • Parsteiner See
  • Tollensesee
  • Oberuckersee and Unteruckersee

• Fjord lakes:
  • Ammersee (?)
  • Lake Constance , also known as tectonic sink to consider
  • Lake Geneva , also to be regarded as a tectonic depression
  • Lakes of the Salzkammergut
  • Carinthian lake area
  • Italian lakes in the alpine area from Lake Garda to Lake Lugano

• recent examples (still today on the edge of the glacier):
  • at the end of the Pasterze (Großglockner)
  • on the Trift Glacier (Gadmen)
  • at the foot of Svartisen

See also

• Ice reservoir - a lake on the edge of the glacier that is not held up by the edge moraine but by the glacier itself
• Kar (valley shape)
• Glacier milk

Web links

Commons : Glacier Edge Lakes  - Collection of images, videos and audio files