Aerial view of the San Andreas fault, California.
The Earth's crust is broken up into a series of plates that sit on the mantle below. Heat, generated from radioactivity deep in the Earth's mantle, drives convection currents that move the crustal plates in different directions, as explained by UCMP. The various plates form three different types of boundary: divergent, in which they move in the opposite directions; convergent, in which they collide; and transform boundaries, in which two plates move side by side.
Why do Earthquakes Occur?
Earthquakes can occur at all three types of plate boundary. BBC News explains how, at plate boundaries, the plates can become locked together, with a subsequent buildup of kinetic energy. When the plates give way, this stored energy is released in the form of an earthquake. The power released by the earthquake happens in three waves of energy: P waves, which are felt as a sudden jolt; S waves, which arrive a few seconds later and produce more sustained side-to-side shaking; and finally, surface waves, which radiate outward from the epicenter, arriving after the P and S waves.
Impact on the Landscape
The powerful and destructive nature of earthquakes means that they play a significant role in shaping the natural landscape along current, and previous, plate boundaries. This occurs over long periods as a result of processes of erosion and deposition along fault lines. Furthermore, according to David Keefer of the U.S. Geological Survey, the material that earthquakes dislodge can form landslides, which can subsequently block waterways and form artificial dams. Thus in the long term, the action of earthquakes will shape the surrounding landscape.
Consequences for the Local Population
According to Randy Kobes and Gabor Kunstatter at the University of Winnipeg physics department, earthquakes are notoriously difficult to predict because of the lack of regular patterns. This, therefore, has implications for the people located in earthquake-prone areas. The result is a need to spend on adequate technology to provide the most effective warning systems as possible, in addition to ensuring that all buildings are engineered to withstand more severe earthquakes. These measures will add to the living costs within these areas. Moreover, the constant threat of a potential earthquake can have long-term mental implications for some people, who may feel as though they live in a constant state of fear and uncertainty. Ultimately this can lead to a reduction in local population, with feedback effects on house prices and the economy.
Potential Impact on Tourism
An area that depends on tourism to support a large part of its economy can be heavily impacted by earthquake occurrence. For example, a decline in tourism can be expected in an area that has recently witnessed an earthquake with a high level of media coverage. The result of this would be further damage to the local economy, which will be bearing the already high costs of the earthquake itself. Moreover, through time, the number of visitors will decline due to fears over safety.
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