Coastal erosion
From Wikipedia, the free encyclopedia
Coastal erosion (or shoreline erosion) is the loss of subaerial landmass into a sea or lake due to natural processes such as waves, winds and tides, or even due to human interference. Large storm-generated waves typically cause coastal erosion, which may take the form of long-term losses of sediment and rocks, or merely in the temporary redistribution of coastal sediments. Coastal erosion may result in coastal accretion at other nearby locations. These processes are also known as coastal morphology or coastal morphodynamics.
On rocky coasts, coastal erosion can result in dramatic rock formations in areas where the coastline contains stones with different resistances to erosion. The softer areas become eroded much faster than the harder ones, which can result in interesting landforms such as tunnels, bridges, columns, and pillars.
On sedimentary coasts, coastal erosion typically poses more of a danger to human settlements than it does to nature itself. Dunwich, the capital of the English medieval wool trade, disappeared over the space of a few centuries due to redistribution of sediment by waves. Human interference can also increase coastal erosion: Hallsands in Devon, England, was a coastal village that was washed away overnight, an event possibly exacerbated by dredging of shingle in the bay in front of it.
The California coast, which has soft cliffs of sedimentary rock and is heavily populated, regularly has incidents of housing damage as cliffs erode. Damage in Pacifica is shown at right. Devil's Slide, Santa Barbara and Malibu are regularly affected.
