Earthquake is defined as any sudden shaking of the ground caused by the passage of seismic waves through Earth's rocks.

Seismic waves are produced when some form of energy stored in Earth's crust is suddenly released, usually when masses of rock straining against one another suddenly fracture and "slip."

Experts said earthquakes usually occur along geologic faults, narrow zones where rock masses move in relation to one another.

Here are the most deadly and devastating earthquakes that happened since 1950:

Sumatra, Indonesia (December 26, 2004)

A magnitude 9.1 submarine earthquake occurred along the Indian Ocean subduction zone, which later triggered a massive tsunami that destroyed 800 km of the coastal areas of Aceh Province.

Experts said that there was ah inundation observed as far as 6 km inland.

Authorities bared that post damage and loss assessment had staggering numbers on the calamity that included more than 220,000 human fatalities and the destruction of 139,000 houses, 73,869 hectares of agricultural lands, 2,618 kilometers of roads, 3,415 schools, 104,500 small-medium enterprises, 13,828 fishing boats, 119 bridges, 669 government buildings, and 517 health facilities.

Records have also shown that a total of 1,089 worship places, 22 seaports, and 8 airports and airstrips had been damaged. Further, more than half a million tsunami survivors were internally displaced and hundreds of thousands more had lost their livelihoods.

The epicenter was 250 km southeast of Band Aceh, Indonesia, at a depth of 30 km. Several days later, a mud volcano began erupting near Baratang, Andamar Islands, which was thought to have been associated with the earthquake.

Haiti (January 12, 2010)

The 7.0 magnitude earthquake struck near Port au Prince in which an estimated 3,500,000 people were affected by the quake. Authorities said that around 220,000 individuals were killed during the powerful quake while more than 300,000 have been wounded.

Further, more than 188,383 houses were badly damaged and 105,000 were destroyed by the earthquake (293,383 in total), with 1.5 million people became homeless.

After the earthquake, there were 19 million cubic meters of rubble and debris in Port au Prince - which was enough to fill a line of shipping containers stretching end to end from London to Beirut.

Peru (May 31, 1970)

The epicenter of the earthquake was under the Pacific Ocean about 15 miles (25 km) west of Chimbote, a fishing port in the department of Ancash, north-central Peru. It occurred at about 3:20 PM local time and had a magnitude of 7.9.

The adverse effects of the earthquake could be felt from the northern city of Chiclayo south to the capital city of Lima, a distance of more than 400 miles (650 km). The most damage occurred in the coastal towns near the epicenter and in the Santa River valley.

It was said that approximately 70,000 people died following the strong quake.

Sichuan, China (May 12, 2008)

The Sichuan earthquake claimed the lives of at least 90,000 individuals, with 375,000 injured, and more than 5,000,000 homeless across the region.

Further, more than half of the town of Beichuan was destroyed by the initial seismic event and the release of the water from a nearby lake.

The quake brought enormous devastation to the mountainous central region of Sichuan province that is located in southwestern China. The epicenter of the magnitude-7.9 quake (measured as magnitude 8.0 by Chinese scientists) was in the city of Wenchuan, about 60 miles (100 km) north-northwest of Chengdu, the provincial capital.

Kashmir, Pakistan (October 8, 2005)

The magnitude-7.6 quake took place in the Pakistan-administered portion of the Kashmir region and the North-West Frontier Province (NWFP) of the country.

It had affected adjacent parts of India and Afghanistan and it also left at least 79,000 people dead. More than 32,000 buildings collapsed in Kashmir, with additional fatalities and destruction reported in India and Afghanistan.

Due to its effects, this quake is considered as one of the most destructive in the contemporary period. The timing of the earthquake added to the misfortune because it left hundreds of thousands of survivors exposed to the coming winter weather.

Sendai, Japan (March 11, 2011)

The magnitude 9.0 earthquake resulted in the death of at least 10,000 individuals.

The aftershocks and tsunami also resulted in adverse conomic impacts, with the shutting down of nuclear reactors that many industries rely on for power.

The earthquake was caused by the rupture of a stretch of the subduction zone associated with the Japan Trench, which separates the Eurasian Plate from the subducting Pacific Plate.