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Explain fully how earthquakes occur - Leaving Cert Geography - Question 1 - 2008
Question 1
Explain fully how earthquakes occur. In your answer refer to a named example which you have studied.
Worked Solution & Example Answer:Explain fully how earthquakes occur - Leaving Cert Geography - Question 1 - 2008
Step 1
How Earthquakes Occur
Answer
Earthquakes primarily occur due to the movement of tectonic plates within the Earth’s crust. This geological activity leads to stress accumulation along faults, which are fractures in the Earth's crust where blocks of land have moved relative to each other. When the stress exceeds the strength of the rocks, failure occurs, releasing energy in the form of seismic waves, which we experience as earthquakes.
The movement can be caused by various factors, including:
- Tectonic Plate Movement: The Earth's lithosphere is divided into several tectonic plates that float on the semi-fluid asthenosphere beneath them. Their interactions at plate boundaries (convergent, divergent, and transform boundaries) can result in earthquakes.
- Volcanic Activity: Earthquakes can also be associated with volcanic activity, as the movement of magma can generate seismic waves.
The intensity and impact of an earthquake are measured using the Richter scale or the moment magnitude scale.
Step 2
Named Example: The 2011 Tōhoku Earthquake
Answer
A prominent example of an earthquake is the 2011 Tōhoku earthquake that occurred off the coast of Japan on March 11, 2011. This earthquake, which reached a magnitude of 9.0, was caused by the subduction of the Pacific Plate beneath the North American Plate.
The strain built up along the Japan Trench over time until the stress released suddenly, resulting in the devastating earthquake. It triggered a massive tsunami that affected the northeastern coast of Japan, leading to significant loss of life and widespread destruction, especially at the Fukushima Daiichi Nuclear Power Plant.