How Natural Processes Operate at Coastal Geographic Environment
Natural Processes are actions or events that have natural causes, which result in natural events. The three main coastal environment processes that operate at Muriwai are Coastal Erosion, Coastal Transportation and Coastal Deposition.
The elements that interact to produce natural processes are wind, waves and tides. Each phenomenon at Muriwai's coastal geographic environment has been produced by interaction.
Coastal Erosion is a process at Muriwai that gradually wears away the rock particles of the earth's surface, transporting them to another location. There are many types of processes that cause erosion at Muriwai such as wave erosion, wind erosion and wave refraction.
Thousands of years ago when sea levels dropped over years at the Southern end of Muriwai, the sedimentary rock and sandstone was exposed to the air. Rock from volcanic activity mixed with the sedimentary rock; this is called Breccia -- a mixture of all rock. An example of this is at Maori Bay.
Coastal Erosion operates at different rates and different times. Limestone rock is eroded slower than sedimentary rock. The cliff at Muriwai made of sedimentary rock was eroded back to expose 'Fisherman's Rock' - the shore platform which, made of limestone -- tended to erode back slower than the cliff.
The types of wave erosion that caused this are -
Hydraulic Action, when waves hit the cliff, air is forced into cracks, and then as the wave retreats this air expands explosively. Over time the cracks enlarge, weakening the base of the cliff causing erosion.
Attrition is the breakdown of rock particles when they hit Otakamiro point and each other causing the base of the headland to erode.
Chemical Erosion/Corrosion occurs due to the content of limestone in the rockface of Otakamiro point. The seawater combined with the limestone produces a weak chemical solution, which erodes the base of the cliff and produces a pitted effect.
Chemical Weathering is when water weakens the structure of the rock and Mechanical Weathering is where water seeps into the rock face causing fragments of rock to break off.
These types of erosion have caused the formation of several phenomena at Muriwai.
Motutara Island (stack) was produced by the formation of two caves on either side of the headland -- forming an arch and the roof slowly erodin...
... middle of paper ...
...ll build up the dunes and travel inland.
Surface Creep occurs when landing sand particles remove the larger and heavier particles, pushing them forward.
Suspension is the picking up of sand by wind. This is when sand is airborne and then deposited anywhere.
Coastal Deposition is the third main natural process occurring at Muriwai's coastal geographic environment.
It is the process of sediment being deposited to form natural features.
This is when the rock fragments from Otakamiro Headland are ripped away by waves, broken down by attrition and transported along the coast where they are deposited as beaches and sand dunes. The movement of the material is called Longshore Drift; the direction of the deposit depends on the direction of the winds.
Titomagnetite sand (black sand) was deposited at Muriwai when it was bought from the south by Longshore Drift.
Coastal Erosion, Coastal Transportation and Coastal Deposition are natural processes that have occurred at Muriwai's coastal geographic environment. These processes outlined have formed such phenomena as Motutara Island (stack), Otakamiro Point (headland/cliff), Fisherman's Rock (shore-platform), cave and the blowhole.
An increase in pebble roundness in the direction of long shore drift. The process of attrition will erode the pebbles. c) A decrease of pebble size in the direction of long shore drift, again attrition is involved. d) Undercutting (active erosion of the cliffs at one end of the bay).
Investigating the Geographical Processes that are Affecting the Physical and Built Coastal Environment There are three geographical processes that are affecting the physical and built coastal environment, they are; erosion, deposition, and transportation. Erosion is the group of natural processes, including weathering, dissolution, abrasion, corrosion, and transportation, by which material is worn away from the earth’s surface, this is mainly caused by wind, running water, and waves breaking on the coast. Deposition is the depositing something or the laying down of matter by a natural process. Transportation is when sand is moved along the coast by long shore drift. At North Cronulla beach erosion is evident.
Barrier Beaches stretch along the entire east coast of the United States. The barrier beaches from Long Island to Maine are known as Glaciated Coasts because their formation was assisted by glaciers. Eighteen thousands years ago a glacier covered most of the eastern US. This glacier terminated at present day Long Island. About fifteen thousands years ago the glacier began to retreat. As it melted it left behind mounds of rubble, called moraines. This particular glacier left behind two moraines because its final recession was a two part process. These two moraines are the Ronkonkoma Moraine and the Harbor Hill Moraine. The Ronkonkoma Moraine is located in central Long Island and the Harbor Hill Moraine is located on the northern part of Long Island. Besides the two moraines the glaciers deposited great amounts of debris offshore. This debris supplies the sand needed to create and maintain a barrier beach system (Hoel 16-18).
The coastal belt of the Franciscan Complex is composed of the youngest and least deformed units and makes up the western quarter of all Franciscan rocks. The rocks of the coastal belt are composed of arkosic sandstones, andesitic graywackes, and quartzofeldspathic graywackes interbedded with radiolarian chert (turbidite deposits) (Blake and Jones, 1981). These sedimentary rocks suggest a depositional environment of deep-sea fan systems with both oceanic and continental provenance. Parts of the belt show evidence of later metamorphism, principally due to subduction. Low-grade blueschist mineral facies are indicated by the presence of minerals such as laumonite and prehnite-pumpellyite (Blake and Jones, 1981). All rock units show evidence of thrust (imbricate) faulting due to the compressional forces of subduction. Ages of the coastal belt run from as little as 40 Ma (Eocene) to as old as 100 Ma (middle Cretaceous).
Abiotic factors are things that are nonliving that influence an environment and it's inhabitants. Some of the abiotic factors that are attributed to coastal erosion in Louisiana are hurricanes, tropical storms, elevation, sunlight, overnutrition, sea-level rise, and deposition. Hurricanes bring about larger waves which cause dune erosion or beach erosion (Clark et al., 1998). This is significant because beaches and/or the dunes of the beach serve as buffers to the coastline and the ecosystem. As the beach or dunes recede from the erosion caused by these large waves and an increased sea-level the flora and fauna that help sustain the area die off or retreat to a more habitable zone leaving the wetlands in a critical state often resulting in a total loss of the area (Stockdon et al., 2012). Due to the nature of the Gulf of Mexico large destructive storms such as hurricanes or tropica...
hard rock is eroded, it can cause an island of hard rock left of the
wind exposure and salt crystallization. It is a type of salt weathering common on coastal and
The financial health of GM has been rocky over the last decade, one remarkable moment being the filing of bankruptcy and the subsequent government bailout. There have been many ups and downs for the corporation but for the last few years (Figure 4) profits again have risen to be the standard. Since the company’s recovery from bankruptcy their status has stabilized financially and in performance. Something is to be said that they have been in business for over 100 years and are still going strong earning them once again the title of top automobile manufacturer of the world.
Dick Durbin and Orrin Hatch first introduced the Dream Act on August 1, 2001 (The DREAM Act). The purpose of the DREAM Act is to help undocumented immigrants have the opportunity to enlist in the military or to attend college and have a path to citizenship (The DREAM Act). In order for these immigrants to be able to be eligible, they have to meet five requirements. First, they must have entered the United States by the age of sixteen. Second, they must have been present in the US for at least five consecutive years prior to enactment of the bill. Third, they must have graduated from a US high school, have a GED, or been accepted into a college. Fourth, they must be between the ages of twelve and thirty-five at the time of applying. Lastly, they have to have good moral character (Basic Information About the DREAM Act Legislation).
Scott, M. (. (2005). Police discretion Thousand Oaks, CA: Sage Reference, 2005. 337-339. Gale Virtual Reference Library. Web. Retrieved: March 2, 2010
Full enforcement is defined by the practice of police officers making an arrest for every violation they encounter. Selective enforcement relies on the judgment of the individual officer to determine which laws to enforce (Bohm & Haley, 2012). The writer has already stated that police officers cannot be expected to
This leads to the next topic full enforcement and selective enforcement. Selective enforcement is relying on the judgment of the police leadership and the rank-and-file of officers to decide which laws to enforce and to decide on important matters
Thus, the purpose of this essay is to examine the debate of the two surrounding arguments where some have contended that an efficient and practical criminal justice system relies on police discretion as it allows the police to be flexible during times of scarce resources. Whereas, many scholars have explored the encompassing limits to this discretion such as issues of accountability, the ability to abuse such powers and perhaps the most precarious consequence of police discretion;
Sediment maturity is due to the transportation and environment of sediment. There were two types of sediment maturity, the texture of grains and the composition in the rocks. Grain textures were the roundness of grains and sediment sorting and presence of clay (Bokman, 1955). The definition of roundness was the ratio of average radius of corners and edges and the radius of maximum inscribed circle (Richard, 1988). The rounding of grains was due to the energy, duration and mechanism of transport. Grain surface textures can be angular and rounded. Quartz was the most abundant minerals. We can use quartz for an example to classify the surface texture of grains. Angular grains of quartz would have conchoidal fractures and could be formed in glacial environment. Quartz grain which was water-deposited had rounded grain and grooves surface caused by impaction of other sediments (Richard, 1988). Quartz grain in aeoli...