What is an Escarpment?

Rock climbing on the side of the Niagara Escarpment.
Rock climbing on the side of the Niagara Escarpment.

An escarpment is a geographical feature that is characterized by a long cliff or a steep slope. These slopes are formed either by fault action or by erosion. Sometimes, the word “escarpment” is interchanged with the word “scarp.” However, in the strictest sense, the two words mean two different things. The word escarpment is used to refer to the difference in height between two landforms while a scarp is used to refer to the slope or a cliff formed after the formation of an escarpment. The surface of this steep slope or cliff is known as the scarp face.

Escarpments are the features responsible for separating land surfaces of equal height. A good example of an escarpment is a feature that separates high plateaus from the lower plains. An escarpment is also a feature that separates two pieces of different lands such as the area at a rocky beach where a steep rocky cliff gives way to a sandy beach. Depending on the mode of formation and age, the lower lying piece of land and the higher one may or may not be from the same geological period.

Formation Of An Escarpment

The processes that form scarps and escarpments are quite similar as the two features are related. These processes are the varying erosion of sedimentary rocks and fault action. When the earth’s crust moves along a fault, it may leaded to the formation of two landmasses that have differing levels of elevation. The exposed slope created is known as a fault scarp while the feature itself is what is known as an escarpment. This mode of formation sometimes leads to the formation of earthquakes of varying degrees. An example of such an escarpment is the Elgeyo Escarpment and some areas of the Great Rift Valley in Kenya. The fault action that led to the formation of the former escarpment turned previously level land into nigh vertical cliffs.

Geological action along fault lines is not unique to Earth alone. An escarpment can form in any planet that has varying contraction and expansion of the crust, which leads to the formation of fault lines. This process happens in other planets and bodies such as Mercury, the moon, and Mars. However, should they happen on other planets or bodies, they are known as “rupes,” which is a Latin word meaning cliff.

Erosion forms escarpments through natural erosive elements such as water and wind. One side of a piece of land may be eroded more than the other side. Consequently, sedimentary rock of different structures and age are exposed on one side. Aside from escarpments, this process can also cause the formation of some strange formations. An example of such an escarpment in the world is the Niagara Escarpment in the US and Canada. Since softer rocks were on the base, erosive action weakened the base. Eventually, the weakened base crumbled due to the heavier weight on top thus leading to the formation of the escarpment as it is today.


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