Cryptodepression

A cryptodepression is a depression in the Earth's surface that is below mean sea level, and which is filled by a lake.[1][2] The term is derived from the Ancient Greek word κρύπτoς ('hidden') and depression.

Prealpine lakes in Northern Italy by elevation (surface and deepest point elevation). Lake Maggiore, Lake Lugano, Lake Como and Lake Garda are cryptodepressions.

Description

A cryptodepression is often due to creation of a rift valley or a glacial lake.[3]

Lakes are often long and narrow. Further, the surrounding landscape and the shore of the lake can be very steep.[4]

Examples

 
Simple calculation example:
Lago O'Higgins/San Martín
Surface elevation  250 m -
Maximal depth      836 m =
_________________________________
Cryptodepression  -586 m
  • Glacial lakes and moraine-dammed lakes: major prealpine lakes in Italy have cryptodepressions created by erosion. In other parts of the Alps, Swiss, Bavarian and Austrian lakes, cryptodepressions are not found because the lakes have significantly higher elevations. Glacial lakes creating cryptodepressions also occur in Norway, Chile, Argentina, Newfoundland, New Zealand, and Scotland. In North America, two of the Finger Lakes in New York, Cayuga Lake and Seneca Lake, are examples of cryptodepressions.
  • Rift valleys: the deepest known cryptodepression on Earth is in Lake Baikal (-1200 m).[4] Other notable examples include Lake Tanganyika and Lake Malawi in Africa's East African Rift.

References
  1. Fairbridge, R. W. (1968), "Cryptodepressions", in Fairbridge, R.W. (ed.), Geomorphology, Encyclopedia of Earth Science, Encyclopedia of Earth Science, Berlin: Springer, Geomorphology, pp. 231–233, doi:10.1007/3-540-31060-6_78, ISBN 978-0-442-00939-7
  2. Neuendorf, K.K.E.; Mehl, Jr., J.P.; Jackson, J.A. (2005). Glossary of Geology (5th edition). Alexandria, Virginia: American Geological Institute. p. 155.
  3. "criptodepressione". Enciclopedia Treccani (in Italian). Retrieved 11 October 2013.
  4. Fairbridge, R. W. (1968), "Cryptodepressions", in Fairbridge, R.W. (ed.), Encyclopedia of Earth Science, Geomorphology, Berlin: Springer, archived from the original on 12 October 2013, retrieved 11 October 2013
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