• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Evaluate how plate tectonics theory helps our understanding of the distribution of seismic and volcanic events.

Extracts from this document...

Introduction

´╗┐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. ...read more.

Middle

The discovery of destructive margins added more solidity to plate tectonic theory and also helped to show why volcanoes occur at these margins. Destructive margins occur when the plates converge, and the denser plate is then subducted and destroyed below the top plate. This usually means a continental plate subducts an oceanic plate, but oceanic-oceanic convergences do also occur. Earthquakes occur in these regions due to the friction caused during subduction, which can explain the distribution of such seismic events like the 2004 Indian Ocean Tsunami. Volcanic activity also occurs at these margins; as the subducting plate is destroyed, the rock melts, and this magma rises up through the surface, manifesting itself as a volcanic eruption. This means that tectonic theory is useful for understanding why volcanic arcs appear on islands like Japan, whose volcanoes make up one quadrant of the ring of fire. As well as this, plate tectonic theory can help us understand how volcanic arcs are formed, as these are created when oceanic plates collide, producing the same volcanic events, which is how Indonesia was created. ...read more.

Conclusion

This occurred on the Pacific plate, resulting in the Hawaiian island arc, which ends with active volcanoes, such as Mauna Loa the island currently above the hotspot. This means that despite its apparent irrelevance, which was first seen to refute plate tectonic theory; this demonstrates that plate tectonic theory can help to explain anomalous tectonic events. There are also further seismic events whose distribution cannot be explained by plate tectonic theory, as they were of human creation. For instance, 200 small earthquakes were triggered when the Hoover Dam in the US was being filled; these earthquakes were not connected with any fault line or plate movement. Earthquakes in the UK have also been a result of fracking, where shale gas is extracted through drilling the crust, which has resulted in minor earthquakes in Blackpool of around 2.3 on the Richter scale. This demonstrates that although plate tectonic theory can explain the majority of seismic events, it cannot explain occurrences such as these. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Hazardous Environments section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Hazardous Environments essays

  1. Marked by a teacher

    Discuss the degree to which the theory of plate tectonics is supported by seismic ...

    5 star(s)

    This essay will evaluate the extent to which this is true, and thus how far the theory of plate tectonics is supported by such phenomena. Volcanoes are openings in the earth's crust through which lava, ash and gases erupt. Lava is taken as proof of the magma that comprises the mantle beneath the earth's crust.

  2. Marked by a teacher

    Volcanic & Seismic events are pieces of evidence proving that the plate tectonics theory ...

    4 star(s)

    It is the location of these eruptions often nearby to many others, linked with the nearby deep sea trench as well as the lava erupted from the ocean floor that prove the plate tectonics theory further. Volcanic events can also occur at constructive margins, and rather than crust being destroyed,

  1. Marked by a teacher

    The number of fatalities that result from volcanic and seismic natural hazards is related ...

    4 star(s)

    Over 45 million people in 10 provinces were affected and 15 million people were evacuated from their homes; over 5 million buildings were destroyed and 21 million damaged in Sichuan which left at least 5 million people homeless; some towns were completely destroyed; the total economic loss was estimated at

  2. Volcanic & Seismic events are major factors towards proving that the plate tectonics theory ...

    Volcanic events and their distribution also shows tell tale signs of the presence of plates and are often found at destructive plate margins, where in many cases the oceanic crust is forced below the continental crust, as the lithosphere descends slides below, large amounts of friction is created and in turn heat leading to melting of the crust.

  1. Evaluate the evidence for the Earths structure & plate tectonic theory

    There are similar glacial deposits which are found in Antarctica, South America & India (from the last ice age); now they are many thousands of kilometres apart.

  2. Continental Drift - the evidence that supports the theory.

    Although Africa has not made contact with Eurasia, small plates caught between the two larger plates have been pushed up against Europe causing mountain building there. The Himalayas formed when north-bound India crashed into Asia. The eastern edge of India made first contact with Indochina perhaps 45 million years ago

  1. To what extent can the theory of plate tectonics explain global distribution of ...

    Similar glacial deposits have been found in India, South America and Antarctica which are now situated thousands of kilometres apart. During the 1950s continental drift became an interest as a result of new found evidence from paleomagnetic studies, which was relatively new at the time.

  2. The World Distribution of Population is as important as the world distribution of areas ...

    lowering global temperatures by around 2 degrees on average in 1980 and grounding international air traffic, the argument for sparse populations not needing population distribution as a dominant strategy in prediction hazards can be proved. This is because the hazards were mainly environmental rather than deaths as in sparse population

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work