Cliffed coast
A cliffed coast, also called an abrasion coast, is a form of coast where the action of marine waves has formed steep cliffs that may or may not be precipitous. It contrasts with a flat or alluvial coast.
Formation
In coastal areas in which the land surface dips at a relatively steep angle below the water table, the continuous action of marine waves on the coastline, known as
In the case of the large and widespread coastal cliffs of Atacama Desert the modern cliffs originated from a process of scarp retreat of a fault scarp, thus at present the cliffs does not follow any geological fault.[3]
Rocky cliffed coast
On a rocky cliffed coast made up of material which is relatively resistant to erosion such as sandstone, limestone or granite, a flat rocky
If waves carve notches at a narrow point on both sides of a promontory on the rocky cliffed coast, a natural arch may be formed.[4] When the arch collapses as the coastline recedes further a stack is left behind on the wave-cut platform. The best-known example in Germany is the Lange Anna on Heligoland, while, in England, a prominent example are Old Harry Rocks in Dorset.
Furthermore, on a rocky cliffed coast wave action is not the only driving force for coastline retreat. General weathering of the bedrock is almost equally important.[2]
Living and dead cliffs
"Living cliffs" are those on a coast that is still active, i.e. that is being eroded and is receding. A "dead cliff", by contrast, is only reached by very high marine waves and is therefore subjected to very little change. A clear indication of a lack of activity at a dead cliff is a covering of vegetation that appears on the cliff as wave action against it subsides.
Well-known coasts with living cliffs in Germany are the Red Cliff (Rote Kliff) in Kampen on the island of Sylt or the chalk cliffs on the Jasmund Peninsula. The Königsstuhl on the island of Rügen is a good example of a dead cliff. Others may be found in the regions of the present-day Wadden Sea coast of the North Sea a few kilometres inland. These show the former coastline from which the sea retreated as the level of water in the North Sea fell.
Other processes
Steep sea cliffs can also be caused by catastrophic
References
- ISBN 0-14-051094-X.
- ^ a b Herbert Louis and Klaus Fischer: Allgemeine Geomorphologie, de Gruyter, 4th ed., Berlin 1979, pp. 532-537
- ^ Paskoff, R. (1979). Sobre la Evolución Geomorfológica del gran acantilado costero del Norte Grande de Chile. Norte Grande (in Spanish). Universidad Católica de Chile, Instituto de Geografía, 6, 7-22.
- ^ Hans Georg Wunderlich: Einführung in die Geologie, Band I, Exogene Dynamik, Bibliographisches Institut Mannheim/Wien/Zürich, B.I.-Wissenschaftsverlag, Mannheim, 1968, p. 116
- ISBN 978-1-4020-6511-8
- ^ Mitchell, N. (2003) Susceptibility of mid-ocean ridge volcanic islands and seamounts to large scale landsliding. Journal of Geophysical Research, 108, 1-23.