The Human Impacts of Tectonic Landforms & Hazards

Human impacts of tectonic activity Why live in tectonically active areas? Lack of knowledge: Even today there are people who do not understand why or where tectonic activity takes place. Tectonic activity does not only take place at plate boundaries – intra-plate earthquakes, e.g. Bam, Iran. This leads people to think it won’t happen to them. The developing world has fewer resources or expertise to study the natural environment (or human environment) – methods to identify areas at risk may not exist (e.g. poorer levels of education), especially if the area is not very active. Pompeii – a classic case of ignorance to disaster. The lack of an eruption in ‘living memory’ led many to believe that Vesuvius was dormant. In 79AD there was no expectation of an eruption – people were caught completely unaware. At the time, the science was not understood – many believed the eruption, and preceding earth tremors were the gods’ anger. Choice: Some people know the risks, but lack financial resources, or have close links to family in the area, and are therefore unable/unwilling to move. Other choose to stay, as the benefits outweigh the costs, e.g. Southern California – well paid jobs and a pleasant climate outweigh concerns over earthquake risk. The benefits of tectonically active areas: Minerals and natural resources – volcanoes bring valuable resources to

  • Word count: 707
  • Level: AS and A Level
  • Subject: Geography
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Explain why tectonic processes produce a variety of contrasting landscapes 70 marks

“Explain why tectonic processes produce a variety of contrasting landscapes.” 70 marks PLAN: . Wegener’s theory of plate tectonics 2. Pangea and how the earths landscape has changed globally 3. Features of oceanic plates: abyssal planes; mid ocean ridge – mountain ranges/islands; sea mounts – volcanic hotspot chains 4. Features at boundaries: ocean trenches at subduction zones; fold mountains; volcanos – volcanic island arcs; faults – San Andrea’s 5. Features of continental crust: folding of curst; Folding and faulting 6. Intrusions – tors/batholiths/dykes/sills (due to erosion/ weathering) – not by tectonics! 7. Flood basalts In my report I am going to discuss how the seven major tectonic plates move around the earth and produce the different structures found at the surface of the planet, and have resulted in varying land formations over the earth’s history. To do this I am going to use a variety of case studies to support the theories of formation and provide evidence for my argument. My case studies are as follows: . Mid Atlantic ridge/ Iceland 2. Hawaiian emperor seamount range 3. pacific abyssal plane 4. Marinas trench 5. Himalayas 6. Japan 7. San Andrea’s fault 8. Cyprus 9. Whin sill 0. Dartmoor tors 1. Siberian traps As well as evidence of how tectonic activity has shaped the landscape I will also be looking at external

  • Word count: 2003
  • Level: AS and A Level
  • Subject: Geography
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Evaluate how plate tectonics theory helps our understanding of the distribution of seismic and volcanic events.

Evaluate how plate tectonics theory helps our understanding of seismic and volcanic events (40 marks) Plate tectonic theory suggests that the earth’s crust is made up of 8 main plates, as well as many other smaller ones. These plates float a top the asthenosphere and are constantly moving, thus constantly interaction with one another. This movement leads to volcanic and seismic events. Such knowledge of plate margins and their interaction can help us to understand the distribution of such events; this is because the majority of events are associated at such margins. Plate tectonics theory was initially developed in 1912 by Wegener. His report but forward the theory of continental drift, suggesting that the continents were once joined as a supercontinent, Pangaea. Plates have since moved apart, and this continental drift is what leads to volcanic and seismic events. Oceanic ridges are created when two plates diverge and magma rises between them from the asthenosere, creating new crust. This rising magma manifests itself as a volcanic event known as a fissure eruption. Plate tectonic theory aids our understanding, as it helps us to see how islands along the mid-Atlantic ridge, such as Iceland are formed. Iceland lies a top the mid-Atlantic ridge, thus was created through volcanic activity. Knowledge of tectonic theory helps us to understand why Iceland is an area of high

  • Word count: 887
  • Level: AS and A Level
  • Subject: Geography
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Examine how a glacier operates as a system (25)

Examine how glaciers operate as a system. (25) Glaciers can be classified according to the temperature of their base. In warm based glaciers e.g. the Alps, the base is warmer than the melting point of ice. It’s warmer because of the heat from friction caused by the glacier moving, or because of the geothermal heat from the earth. The ice at the bottom of the glacier melts, and the meltwater acts like a lubricant, making it easier for the glacier to move downhill. Ice at the surface also melts if the temperature reaches 0 degrees Celsius, and meltwater moves down through the glacier, lubricating it even more. Therefore, warm based glaciers move rather quickly, lots of movement means lots of erosion so warm based glaciers are highly erosive too. On the contrary, in cold based glaciers e.g. in Antarctica where glaciers cover 13,586,380km, the base is cold and the temperature is usually well below the ice’s melting point, so there’s very little melting and this lack of meltwater means cold based glaciers move very slowly. The ice is frozen to the valley floor which also slows movement. Even in summer the temperature is below freezing, the mean annual temperature of the interior is −57°C, so there’s not a lot of melting at the surface either. Consequently, cold based glaciers don’t erode a lot. A glacier is a system which has inputs, outputs and stores. The main

  • Word count: 1465
  • Level: AS and A Level
  • Subject: Geography
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Describe The Problem Of Global Warming

The Problems With Global Warming Global warming is the greatest challenge facing our planet. It is, in fact, the increase in the temperature of the earth’s neon- surface air. It is one of the most current and widely discussed factors. It has far-reaching impact on biodiversity and climatic conditions of the planet. Several current trends clearly demonstrate that global warming is directly impacting on rising sea levels, the melting of ice caps and significant worldwide climate changes. In short, global warming represents a fundamental threat to all living things on earth. Global average temperature rose significantly during the past century. The prevailing scientific view is that most of the temperature increases since mid-20th century has been caused by increases in atmospheric greenhouse gas concentrations produced by human activity. Most scientists agree that planet’s temperature has risen 0.5 degree Celsius since 1900 and will continue to increase at an increasing rate. As a result, the world is getting warmer. The year 1990 was the hottest year in the last century. Together with 1991, the years of 1983, 1987, 1988 and 1989 have been measured to be the warmest six years in the last hundred years. The year 1991 was the second warmest year of the past century. The consequences of the rise in temperature is being felt all over the globe the findings of scientific

  • Word count: 1299
  • Level: AS and A Level
  • Subject: Geography
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Describe the characteristic features of a biome of one tropical region that you have studied [10]

Describe the characteristic features of a biome of one tropical region that you have studied [10] The tropical rainforest biome occupies the area 100 North and South of the equator, where the yearly insolation and precipitation is abundantly high. These conditions provide optimum growing conditions for the flora that thrive in this region. Precipitation is the chief determinant of the overall type of vegetation and thus ecosystem development, however soil nutrients is the main limiting factor to the growth for such tropical vegetation. The climate of this biome is characteristically hot and humid, with an unwavering constant yearly temperature of 270C that rarely exceeds 320C. Despite this, the diurnal temperature can vary as much as 10-150C due to the waxing and waning cloud cover throughout the day. Furthermore the annual precipitation is between 2000-3000mm coupled with a high humidity ranging from 80-100%. Due to the proximity to the equator most areas experience an equal split of day-time and darkness. Although the flora of this biome experience a constant growing season, dry seasons can emerge as the ITCZ migrates after the equinox, resulting in lower rainfall and a subsequent increase in average daily temperatures. The vegetation in this area is thought to be the classic climatic climax vegetation of the planet and due to the biomes long term stability over millions

  • Word count: 1184
  • Level: AS and A Level
  • Subject: Geography
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Chaiten Volcanic Eruption Case Study

Chaitén Eruption location map for Chaitén volcano Where did it happen? (written description, map of the location) Chaitén is a small volcanic caldera (cauldron-like volcanic feature normally formed by the collapse of land following a volcanic eruption) located in southern Chile. The volcano is 3km in diameter and is located 17km west of the Michinmahuida volcano and 10km northeast of the town on Chaiten, hence the name of the volcano. When did it happen? (date, duration, sequence of events, pace of management and recovery) The largest and most recent eruption was in May 2008, but before this, the volcano consisted mainly of a rhyolitic lava dome which was last active 9400 years ago. On 2nd May 2008, Chaitén began erupting violently, producing many plumes, pyroclastic flows and lahars, and creating a new lava dome on the north side of the old dome. Chaitén continued to erupt from 2nd May to 8th May with nearly continuous ash emission and irregular large explosions. The eruption has had serious consequences for the nearby town of Chaitén due to the effect s of lahars and ash, and the ash from the eruption even disrupted travel and agriculture in surrounding countries. The plume of steam and ash rose up to 16.8km into the atmosphere on the first day, and continued to do this on the 3rd May. The plume on this day rose over the Andes Mountains, drifted over Argentina

  • Word count: 818
  • Level: AS and A Level
  • Subject: Geography
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Discuss the view that the impacts of volcanic hazards depends primarily on human factors

Discuss the view that the impacts of volcanic hazards depends primarily on human factors There are a wide range of volcanic hazards associated with volcanoes, there are the obvious primary hazards; lava flows, pyroclastic activity and poisonous gas emissions. There are also secondary impacts that result from the eruption such as lahars (sometimes called mudflows), avalanches and debris flows. These are all caused by natural causes but the effects from these can be enhanced or worsened by human factors. There are many different ways that volcanoes can impact the people and environment around it. The hazards from volcanoes can cause death to surrounding populations and also destroy important buildings and the infrastructure nearby. The environment can also be affected due to the gas released from volcanoes and also destruction of environment from pyroclastic flows or lava flows. These can be compounded and the impacts will vary depending on a mixture of human and physical factors. In 1980 in Washington State after 123 years of hibernation Mt St Helens erupted. This volcanic eruption produced many different hazards including a huge landslide, one of the largest ash clouds in recent years and a pyroclastic flow that destroyed huge areas surrounding the volcano. The most devastating of these to humans was the ash cloud. This drifted hundreds of miles and ash fell on 11 states. It

  • Word count: 950
  • Level: AS and A Level
  • Subject: Geography
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The Kobe earthquake.

This project is on the Kobe earthquake. This quake scaled 7.2 on the Richter scale (6-7 on the Japanese scale). The earthquakes epicentre was at the northern Awaji Island and had a depth of 14km. Its total deaths by the 30th of March were 5,477 and injuries 34,900. The earthquake had caused fires that destroyed 7,456 houses, road damage, 171,481 collapsed houses, and a total damage cost of 9,963 yen. In this project there is a graph showing the number of deaths over a period of days on page 2. It shows the increase of the deaths as the days went on. On page 3, the increase of the deaths is described and explained. It shows of reasons why there would be an increase in deaths. On page 4, the effect on the economy is explain and the reasons why are stated. On page 5, a letter written after the quake is enclosed, explain what had and has happened. As the days went on there was an increase in the number of deaths. This was because as the days went on more people died. The increase between the 17th and the 21st of January was a rapid increase from 1247-4412 with a difference of 3165 people. This was within 4 days which the average per day is about 1100 people. The increase between the 21st and the 18th of feburary was not as rapid. From 4412 it rose to a number of 5390 with a difference of 978. The increased really slowed down between the 30th and 18th of February, we can

  • Word count: 1215
  • Level: AS and A Level
  • Subject: Geography
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The Kobe Earthquake.

INTRODUCTION On the 1st of September 1923 Japan suffered its worst ever natural disaster when an earthquake followed by a tidal wave and fire struck Tokyo. The effects were devastating, 99,331 people were killed and 103,733 people were injured. After this event took place every Japanese citizen was issued with a box of essentials in case another earthquake should strike. In addition to this, they were all given a small amount of training and, in more recent times, 500 researchers have been working to predict if and when this could happen again. Despite this, in 1995, an event took place that shocked observers worldwide. KOBE The South-central region of Japan is the second-most populated and industrialized area, after Tokyo, with a total population of about 10 million. Kobe on its own has a population of about 1.5 million and is very economically developed. Kobe is one of the richest cities in the world, producing as much wealth on its own as Canada! The Japanese built their houses traditionally out of wood here as wood was flexible and could bend with the ground if an earthquake took place. In modern times heavy tile roofs were put on top of their houses to sustain the strong winds which blew against them. THE KOBE EARTHQUAKE On the 17th of January 1995, at 5:46am local time, in the South-central region of Japan, Kobe was just beginning another new day. Suddenly a

  • Word count: 1045
  • Level: AS and A Level
  • Subject: Geography
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