If you have ever lived in proximity to coastal areas you may have seen coastline erosion first hand. The beaches you frequent during the summer may seem to be getting smaller and smaller every year. Why does your favorite beach seem to be disappearing? Coastal erosion is to blame. The waves, wind, tides and currents all play a part in the mechanism that is coastal erosion. When water and wind batter the shoreline sediments are carried out to sea and deposited on the sea floor or at other points along the coastline. This is called an erosional coastline. This erosion may be very apparent or seem to have happened overnight when it happens due to a large storm or extremely high tide.
So all coastlines are subject to this abuse from the
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(Chambers, 2007) At this point the headland becomes a sea arch. As time passes water erodes at the base of the sea arch and wind and freezing water create a hydraulic effect in the cracks on the arch portion and eventually it crumbles creating a sea stack. Through further erosion due to wave current tidal and wind action the sea stack eventually wears down to a smaller version of what it was originally, it is now known as a sea stump. The next illustration depicts the processes that encompass the creation of a sea arch through erosion to a sea stump. (Chambers, 2007)
Wave cut platforms are another feature of an erosional coastline. Along coastlines with cliff edges that sit about the shore these features are apparent they look like gently sloping areas of landnear the shore just above sea level. (Chambers, 2007) These benches and marine terraces are the product of wave action eroding the rock at the base of the cliff until the cliff cannot support itself on its new foundation and crumbles into the sea. Over time the collapsed land will have much of the smaller debris eroded away and much of the remaining rock or earth will be somewhat smoothed over to create a gentle slope to the water. (Chambers, 2007)
Here is a picture of a wave cut platform. (Chambers, 2007)
Let’s take a look at the features of a depositional
Seawalls are also strategies that Cronulla and Collaroy implement on their beaches. However, the seawalls in Collaroy are buried under the sand and are only visible after large-scale erosion events. Whereas Cronulla beach’s seawalls are visible and reduce the scenic
Sand dunes are a valid indication of the quality of the soil and the surrounding ocean. When vegetation is established in sand dunes, it stabilises it- i.e. gives the dunes structure. This structure helps prevent erosion by using the plant life to trap the sand. Without these plants (and ultimately the sand dunes) sand will be subject to many natural forces without protection, meaning any major storm could theoretically remove large amounts of sand from the beach with no natural means of replenishing it. Long Reef Beach is commendable in the amount of vegetation it has produced.
The Year 10 geography field trip was an insightful experience into the workings and functioning of metropolitan coastlines here in South Australia. The day consisted of visiting various beaches in Adelaide that were influenced by some form of hard or soft engineering techniques that changed the natural processes of the beaches. What was evident from this trip was how much these beaches have been changed to an extent where it is unlikely that they will ever go back to the way they were prior to human settlement.
There are 2 types of beaches. One is erosion dominant and the other is deposition
* The sand dunes on the beaches. This area is affected by wind erosion as well as the tides if adequate vegetative cover is not present. The main type of erosion, from the sea, takes the sand from the sand dunes as well as the rest of the beach in a rip. The sand is then pulled out to sea where it forms a sand bar. On calmer days, the sand is brought back to the beach.
The more coastal erosion there is, the higher the chance is for saltwater contaminating freshwater resources and the salt from the ocean can cause soil to be uninhabitable to plants (Again this can affect agriculture). Coastal erosion is not only an issue for water resources, it’s also a direct issue for the communities. The communities on islands lay very close to the coast and important infrastructures are one of them. Islands cannot get all of their resources from the local farmers, so they import it via plane or boat. The problem with that is the airports and ports are all on the coast. Coastal erosion has the power to ruin airport runways and docks of the harbors and ports; this means that eventually communities will be starved of basic necessities and there will be no way of getting in basic needs. Not only will airports be ruined, so will our tourism industry. Coastal erosion will eventually ruin the beaches that attract tourists. Island communities depend on the tourism industry because that industry brings in a lot of money every year. Without tourists, communities will struggle financially. Lastly, the ecosystem of the islands will suffer the
be due to the fact that on either side of the headland are two bays or
Erosion is unfortuanately present at Cronulla beach, the local government have tried to tackle this problem with solution such as dune stabilization and rip rap
I examine how rising or falling tide can affect the water level of Corte Madera Salt Marsh in this report. The data is from Wednesday (June 19th) and Thursday (June 20th). My hypothesis is that tide and water level have positive relationship. From the result, I learn that the water level and tide have positive relationship. However, when tide changes its direction, the water level is likely to stay or little change.
There are many different types of coasts that exist throughout the United States. The south shore of Long Island has a unique types of coast known as a barrier beach. Barrier beaches are long narrow land forms that are composed of sand and other lose sediments. These sediments are brought together by the actions of waves, currents and storm surges. Barrier beaches are subject to constant changes by the same forces. Sand is constantly eroded in one area an deposited in another. Barrier coasts are important for a number of reasons; they protect the mainland of Long Island from the open ocean and flooding during storms, for recreational use and the unique ecosystems which exist on barrier
The tiny pieces of rocks broken off by weathering are called sediment or alluvium. Erosion is the process of transportation of this sediment which on sea cliffs sediments becomes part of the seafloor and is washed away with the waves. The larger rocks that are broken off by sediment as shown in this picture are called scree or talus; scree builds up at the bottom of cliffs as the rocks tumble down, these piles are called scree slopes or talus piles.
The definition for erosion is the process of the surface of the Earth being worn down by natural causes such as wind, waves and rain. A type of erosion that impacts on the Gold Coast is the coastal erosion. Coastal erosion is the permanent loss of land along the shoreline. Erosion on Gold Coast beaches occurs mostly to the sand on the beaches where the waves can easily erode away.
Furthermore, extraction of building materials such as sand affects coral reefs, mangroves, and hinterland forests, leading to erosion and destruction of habitats. Overbuilding and extensive paving of shorelines can result in destruction of habitats and disruption of land-sea connections such as sea-turtle nesting spots. Coral reefs are especially fragile marine ecosystems and are suffering worldwide from reef-based tourism developments. Evidence suggests a variety of impacts to coastline ecosystems result from shoreline development, increased sediments in the water, trampling by tourists and divers, ship groundings, pollution from sewage, overfishing, and fishing with poisons and explosives that destroy coral
9. What are the different types of shorelines? Describe each type briefly. There is a rocky coast, lowland beach and barrier island, as well as coral reef. A rocky coast describes the most common type of costal area. This is where there are vertical wave cut cliffs and horizontal bench cut cliffs. The erosion undermines the cliffs and sends the resulting debris into the ocean forming rough outcroppings. Beaches are not only the sand
The erosion of shorelines is a natural process that can have beneficial or adverse impacts on the creation and maintenance of habitats. Sands and gravels eroded from the shores of coastal bays maintain the beach as a natural barrier between the open water and coastal wetlands. Beaches move back and forth onshore, offshore and along shore with changing wave conditions. The finer-grained silts and clays derived from the erosion of shorelines are sorted and carried as far as the waters of wetlands or tidal flats, where benefits are derived from addition of the new material. However, excessively high sediment loads can smother submerged aquatic vegetation beds, cover shellfish beds and tidal flats, fill in riffle