Geomorphology is the study of the surface of the Earth Classically
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Geomorphology is the study of the surface of the Earth. Classically, geomorphologists have studied landforms, which are shapes that have been categorized or named by geomorphologists or other Earth scientists (Mayer, 1990). The types of sandy beaches include sheltered beaches and exposed beaches. Exposed beaches erode far more than sheltered beaches. According to Hegge, Eliot, and Hsu, sheltered beaches may be classified into six various morphotypes. These types of beaches include concave beaches, steep beaches, flat beaches, moderately concave beaches, moderately steep beaches, and stepped beaches. According to a University of California, Santa Cruz website, shorelines can be broadly classed as beach and rocky shorelines.
The elements of a beach shoreline are: the offshore; the foreshore, the inshore, and the backshore. The offshore is defined as everything far enough off shore to be below average wave base (L/2). The foreshore and inshore consists of the breakers, surf and swash zones. The backshore begins at the highest point that swash reaches. Here you will frequently find a berm, a deposit of sand and gravel at the edge of the swash zone. Dunes often occur further from the water and are built of windblown sand (UCSC, 1997).
Beaches exposed to relatively high wave energies generally undergo rapid erosion and accretion in response to storm onset and passage. Such beaches undergo a quasi-cyclic pattern of change, with phases of erosion and accretion occurring over short periods of time (Hegge, 1996).
According to studies conducted by Hegge, Eliot, and Hsu, the above beach morphotypes listed were classified as follows. Concave beaches were characterized by a steep foreshore, a steep swash zone, and a fairly flat inshore zone. Steep beaches were characterized by having a steep and linear beachface slope, as well as, an inshore zone that was usually steep. Flat beaches were characterized by broad, flat and wider nearshore zones, and wider foreshore zones as well. Moderately concave beaches were classified by having similar characteristics to concave beaches with a smaller nearshore slope and lesser concavity than concave beaches. Moderately steep beaches were characterized by steep linear nearshore zones, wide beach faces, and much higher berms. Last, stepped beaches had very narrow nearshore profile, with relatively steep beachfaces.
Rocky shorelines are dramatically different in many aspects. Some aspects include greater water depths close to the shore, much higher land altitudes nearby, and various stages of erosional progression. The main difference between various types of shorelines is due to plate tectonics. Many rocky shorelines are located along plate boundaries, such as the west coasts of North and South America. These areas are considered subduction zones, due to one tectonic plate sliding beneath the other. Over time, continents within these zones buckle causing uplifted terraces. Deep-water trenches are also apparent due to the subduction of plates adjacent to continental plates. Rocky shorelines also occur in areas where there is a lack of sediment. The sediment from a given area of land is removed through both glaciation and erosion(including runoff). After bare rock is exposed along a shoreline, wave erosion begins to wear down the surfaces of the rocky coast. Along many rocky shores various stages of erosional progression, such as the formation of sandy beaches, can be observed. According to the University of California, Santa Cruz’s website rocky shorelines have the following physical attributes.
The elements of rocky shorelines are: a wave-cut bench, wave-cut notch and the wave-cut cliff. The bench is a gently dipping bedrock flat created by surf erosion. It grows in the landward direction by the action of surf cutting a notch at the base of backing cliffs. When the notch grows deep enough, or when storm surges raise wave energy levels sufficiently, the wave-cut cliff will fail (an example of mass wasting). The rock debris is quickly broken down, becoming grist used to scour the wave-cut bench. Beaches on rocky shorelines are usually limited to pockets between headlands. Here wave refraction results in a lower-energy environment where sediment is deposited.
Species richness varies depending the type of shoreline. Rocky coasts seem to have a much higher level of zonation concerning various organisms. This is due to the fact that there are such a limited number of rocky coasts, causing competition for rocky coast organisms to be great. According to studies done by T.A. and Anne Stephenson the zones
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Coastal geography, Intertidal zone, Littoral zone, Beach, Swash, Rocky shore, Erosion, Headlands and bays, Coastal erosion, Sea, Canterbury Bight
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