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Types of Diastrophism in Coastal Plains

Diastrophism occurs when features on the Earth are changed because of deformations of rock and changes in position, caused by events such as earthquakes or folding. Folding is when rocks collapse when too much force is placed on them. The sturdiness of the rock leads to changes in the structure of the surrounding area. Dramatic changes in the coastal plains, brought about by diastrophism, can cause major changes to animal and plant habitats.

Water Erosion
- Coastal plains often have streams cascade off nearby rocks, which can put strain on the rocks because of water erosion. The water can gradually wear away at the rocks, placing greater weight on them and eventually cause the rocks to collapse, leading to a deformation of the coastal plains that change their appearance. The streams can divide the coastal plains into separate sections, especially in the higher and more ancient plains. The flatlands of the coastal plains are poorly drained, leading to areas that flood during heavy rains. The flooding can carry soil into the ocean, which changes the physical nature of the coastal plains.
Glacial Melts
- Coastal plains were originally formed by the rising and falling of the sea levels, which resulted from the melting and growth of the continental glaciers, as an example of a large and long-term form of diastrophism. Glaciers have always existed, growing and shrinking in ways that respond to changing climates and causing dramatic changes in the structure of landscapes throughout the world, with some of most dramatic changes occurring during the Ice Age. One of the longest periods of glaciation lasted 50,000 years.
Earth Composition
- Coastal plains are sandy. The nature of these plains makes them less resistant to forces placed upon them, causing them to collapse more easily. Coastal plains can sometimes be hilly, which results from diastrophism, which can cause elevations and depressions. The low areas in coastal plains are examples of depressions.
Earthquakes
- Some coastal plains, such as those in South Carolina, experience earthquakes, with a 3.6 magnitude earthquake occurring in the low country in 2008. Earthquakes can cause soil to act like dense liquid in a process known as liquefaction.This is caused by water pressure. It can change the nature of the coastal plains by depositing soil in different locations. Elevated areas can experience landslides, which deposit soil in new areas in the coastal plains. Serious earthquakes can even cause portions of the coastal plain to break off and disappear into the ocean.

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