Case Study of Fluvial Landforms and Processes
All rivers aim to reach equilibrium so they are balanced and when they
are in equilibrium from source to mouth a smooth curve is created
called the graded long profile. However, as you can see from the
diagram many rivers such as The Afon Glaslyn, do not acheive
equilibrium and reach their graded long profile:
Long Profile of Afon Glaslyn River with graded long profile
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Rivers become out of equilibrium when there is a change in base (sea)
level. There can either be a positive change (rise) in the sea level
or a negative change (fall) in sea level, resulting to a change in
base level and a new graded long profile. Sea level changes happen
because the Earth is in or out of glacial periods. Therefore sea level
is changed either eustatically- a change in sea level due to a change
in the amount of water locked up in ice sheets, or isostatically- when
the the change in sea level is due to a change in the level of land
caused by growing or retreating ice sheets. The change in base level
affects the long profile of a river and as the river tries to reach
its new graded profile in order to reach equilibrium there are various
processes and landforms found along the river's course. By looking at
The Afon Glaslyn we can see how and why these processes occur and
landforms formed.
The Upper Reaches
0-4km
· Processes
The main process in this section is erosion, in the form of:
attrition, corrasion, hydraulic action and corrosion. Attrition is
when the boulders collide with each other, breaking up into smaller
pieces. Corrasion is when the ,material carried in suspension rubs
against bank of river. Hydraulic action is the rivers force dislodging
particles and finally corrosion is when acids dissolve rock. Erosion
occurs because at this point the river is above its graded profile
(base level decreased) and the lithologhy (made up of hard rock), this
15. The pictures above show how the continents on Earth’s surface have changed position over a very long period of time. What explains this change? (S6E5e, f)
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.
Bonnett, Gabrysch R.K. and C.W. "Land Surface Subsidence at Seabrook, TX ." US Geological Survey. Seabrook TX: Water Resources INV, 1975.
The purpose of this paper is to explain and highlight different aspects of the Powder River Basin to include paleogeography, stratigraphy, maturation history of organic material, vitrinite reflectance data, sulfur content, both historical and current production data, as well as the environmental impact in the basin.
Continental drift- led to the change in the physical features of land, its position and a change in ocean currents.
...lision, sea levels were lower. The poles began to gain ice caps. Due to all the ice, the sea levels dropped even more. With the sea levels decreasing, there was more land between continents for animals to travel across. Due to the continually cooling climates, the earth entered an Ice Age. The lower sea levels and new mountain ranges contributed to it. There were a lot more ice caps than there are today.
Chapter 22 in the novel Regeneration by Pat Barker is very significant to the development of the character Dr. W.H.R. Rivers, through the symbol of control throughout the book. In this chapter, Rivers returns to his home after witnessing Dr. Lewis Yealland’s horrific treatment of his patient Callan through the use of electrotherapy. Being displaced by the incident, Rivers finds it difficult to do any work because throughout the night recollections of the treatment continue to haunt him. After deciding to go to sleep, Rivers has a nightmare where he is treating a patient with electroshock therapy, just as Yealland did, except after attempting to shove the electrode into the patient’s mouth several times, he realizes that what he is holding is not an electrode, but a horse’s bit. Rivers awakens and reflects on this dream, noting that instead of trying to cure a patient of mutism by stimulating the patient with electroshock therapy, he was really trying to get his patient to stop speaking, and to rather become mute. The passages in chapter 22 serves to force the reader to question wether or not Rivers and Yealland are actually helping their patients, as well as to develop Dr. Rivers’s character by showing how he and Yealland are quite similar despite their differences in treatment through the exhibition of the element of control that both of these characters possess.
The Earth’s biosphere is being affected by climate change in numerous ways. The interactions that occur between the hydrosphere and atmosphere are leading to changes in our ocean’s chemistry that could be devastating to humans in the future generations to come. Climate change is the modification in the climate patterns. The effects of climate change have become particularly apparent from the mid to late 20th century onwards and have been substantially contributed to by the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels.
Oceans cover around seventy percent of the Earth’s surface. The oceans of the world have a direct relationship with weather and climate – they influence the weather both locally and globally and the changes in climate in exchange have an affect on properties of the oceans. Changes that occur to the ocean for the most part occur over a much longer period than in the atmosphere. Even if carbon dioxide emissions were to be stabilized today, it would centuries for oceans to adjust to the changes in the atmosphere. When greenhouse gases trap more energy for the sun, oceans then absorb more heat; and in turn there is a rise in sea surface temperatures as well rising sea levels. Oceans do help to reduce climate change due to the fact that they
The "Ocean Events" GRACE â Uncovering the 2010-11 Decline in Global Mean Sea Level and Its Relation to ENSO (October, 2012). N.p., 8 Oct. 2012. Web. The Web.
Hoffman, J. (2007, May). The maldives & rising sea levels [Fact sheet]. Retrieved March 16, 2014, from Ice Case Studies website: http://www1.american.edu/ted/ice/maldives.htm
There is no longer any question that our world climate has changed (King, 2004). Over the last 100 years, "temperatures have risen by about 0.6 degrees Celsius and global sea level has risen by about 20cm" (K...
...o high latitudes will increase rapidly which will cause temperatures to increase as well (National Climatic Data Center).
Climate change is triggering major changes in our planet. A simple rise or fall in general temperature can have a large effect on precipitation patterns and the frequency of storms. The rise in the sea level, which has been accounted for and is constantly rising has been the result of melting of ice and glaciers.
Climate change is largely caused under certain situations and circumstances by factors like variations in solar radiation, ...