maavärinategurite

Maavärinategurid, or earthquake causes, refer to the natural phenomena that trigger seismic activity within the Earth. The primary driver of most earthquakes is the movement of tectonic plates, which are large, rigid slabs of the Earth's lithosphere that float on the semi-fluid asthenosphere beneath. These plates are in constant, slow motion, driven by convection currents in the Earth's mantle.

When these tectonic plates interact at their boundaries, immense stress builds up. This stress is released suddenly, causing the rocks to fracture and shift. The point where the rupture begins is called the hypocenter or focus, and the point directly above it on the Earth's surface is the epicenter. The released energy travels outward in the form of seismic waves, which are detected by seismographs.

There are three main types of plate boundaries where earthquakes commonly occur: convergent boundaries, where plates collide; divergent boundaries, where plates move apart; and transform boundaries, where plates slide past each other horizontally. The type and intensity of the earthquake depend on the nature of the plate interaction and the amount of stress accumulated.

While tectonic plate movement is the most common cause, other factors can also lead to earthquakes. Volcanic activity, particularly eruptions, can cause tremors as magma moves beneath the surface. Human activities, such as the construction of large reservoirs (reservoir-induced seismicity), mining operations, and the injection of fluids into the ground for oil and gas extraction, can also trigger seismic events, though these are generally smaller in magnitude compared to tectonic earthquakes.