Maavärinamehhanism

Maavärinamehhanism refers to the geological processes that cause earthquakes. The Earth's outer shell, known as the lithosphere, is broken into large pieces called tectonic plates. These plates are constantly moving, albeit very slowly, due to convection currents in the semi-fluid layer beneath them, the asthenosphere.

When these tectonic plates interact at their boundaries, stress builds up. This stress can accumulate over long periods as the plates grind against each other, pull apart, or collide. The rocks along the plate boundaries are elastic, meaning they can deform under this stress. However, there is a limit to how much they can deform before they break.

When the accumulated stress exceeds the strength of the rocks, they rupture. This sudden release of energy propagates outwards from the point of rupture, called the focus or hypocenter, in the form of seismic waves. These waves travel through the Earth and cause the ground to shake, which we perceive as an earthquake. The point on the Earth's surface directly above the focus is called the epicenter.

The type of tectonic plate boundary largely determines the kind of earthquake that occurs. Convergent boundaries, where plates collide, can produce very powerful earthquakes. Divergent boundaries, where plates move apart, typically generate shallower and less intense earthquakes. Transform boundaries, where plates slide past each other horizontally, also cause earthquakes as friction momentarily halts their movement, leading to stress buildup and sudden slips.