Most earthquakes occur at or near plate boundaries due to the movement of tectonic plates. The Earth's lithosphere is divided into several large and small tectonic plates that float on the semi-fluid asthenosphere below. These plates are constantly moving, but they can become locked together due to friction. When stress builds up to a point where it overcomes this friction, the plates suddenly slip, releasing energy in the form of seismic waves that we feel as an earthquake.
There are three main types of plate boundaries where earthquakes frequently occur:
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Convergent Boundaries: Here, one plate moves toward another. This can result in subduction, where one plate is forced below another, leading to intense pressure and often causing earthquakes.
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Divergent Boundaries: At these boundaries, plates move apart from each other. As the crust is pulled apart, it can create faults, resulting in earthquakes.
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Transform Boundaries: At transform boundaries, plates slide past one another. The friction between the sliding plates can cause earthquakes, especially where stress accumulates.
While it is true that some earthquakes can occur away from plate boundaries (intraplate earthquakes), the majority are associated with the dynamics of plate tectonics at the boundaries due to the intense stress and strain generated in these regions. This explains why most earthquakes are found near or at plate boundaries.
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