Top 12: Largest Earthquakes by Magnitude
An earthquake (also known as a quake, tremor or temblor) is the result of a sudden release of energy in the Earth’s crust that creates seismic waves.
Mw – Moment magnitude scale is used by seismologists to measure the size of earthquakes in terms of the energy released. The scale was developed in the 1970s to succeed the 1930s-era Richter magnitude scale.
1. 1960 Valdivia Earthquake (9.5 Mw)
The 1960 Valdivia earthquake or Great Chilean Earthquake of Sunday, 22 May 1960 was the most powerful earthquake ever recorded, rating 9.5 on the moment magnitude scale.
It occurred in the afternoon at 15:11, and the resulting tsunami affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand, southeast Australia, and the Aleutian Islands.
2. 1964 Alaskan Earthquake (9.2 Mw)
The 1964 Alaskan earthquake, also known as the Great Alaskan Earthquake and Good Friday Earthquake, was a megathrust earthquake that began at 17:36 on Friday, March 27, 1964.
Lasting 4 minutes and 38 seconds, it was the most powerful recorded earthquake in U.S. and North American history.
Across south-central Alaska, ground fissures, collapsing structures, and tsunamis resulting from the earthquake caused about 139 deaths.
3. 2004 Indian Ocean Earthquake (9.1–9.3 Mw)
The 2004 Indian Ocean earthquake was an undersea megathrust earthquake that occurred at 7:58:49 on 26 December 2004, with an epicentre off the west coast of Sumatra, Indonesia.
The earthquake itself is known by the scientific community as the Sumatra–Andaman earthquake.
The resulting tsunami was given various names, including the 2004 Indian Ocean tsunami, South Asian tsunami, Indonesian tsunami, the Christmas tsunami and the Boxing Day tsunami.
The earthquake and tsunami combined are the world’s deadliest natural disaster (230,210 – 280,000 deaths) since the 1976 Tangshan earthquake (7.8 Mw ; 242,769 deaths).
4. 2011 Tōhoku Earthquake (9.0 Mw)
The 2011 earthquake off the Pacific coast of Tōhoku was a magnitude 9.0 undersea megathrust earthquake off the coast of Japan that occurred at 14:46 JST on Friday 11 March 2011,with the epicentre approximately 70 kilometres (43 miles) east of the Oshika Peninsula of Tōhoku.
The earthquake triggered powerful tsunami waves that reached heights of up to 40.5 metres (133 feet) in Miyako in Tōhoku’s Iwate Prefecture, and which, in the Sendai area, travelled up to 10 kilometres (6 miles) inland.
The tsunami caused nuclear accidents, primarily the level 7 meltdowns at three reactors in the Fukushima Daiichi Nuclear Power Plant complex, and the associated evacuation zones affecting hundreds of thousands of residents.
5. 1952 Kamchatka Earthquakes (9.0 Mw)
The main earthquake struck at 04:58 on November 4, 1952. Initially assigned a magnitude of 8.2, the quake was revised to 9.0 in later years.
A large tsunami resulted, causing destruction and loss of life around the Kamchatka peninsula and the Kuril Islands. Hawaii was also struck, with estimated damages of up to US$1 million and livestock losses, but no human casualties were recorded. The tsunami reached as far as Alaska, Chile, and New Zealand.
6. 1833 Sumatra Earthquake (8.8–9.2 Mw)
The 1833 Sumatra earthquake occurred on November 25, 1833, about 22:00, with an estimated magnitude in the range 8.8–9.2. It caused a large tsunami that flooded the southwestern coast of the island. There are no reliable records of the loss of life, with the casualties being described only as ‘numerous’. The magnitude of this event has been estimated using records of uplift taken from coral microatolls.
7. 1906 Ecuador–Colombia earthquake (8.8 Mw)
The 1906 Ecuador–Colombia earthquake occurred at 15:36 UTC on January 31, off the coast of Ecuador, near Esmeraldas. The earthquake had a magnitude of 8.8 and triggered a destructive tsunami.
8. 2010 Chile Earthquake (8.8 Mw)
The 2010 Chile earthquake occurred off the coast of central Chile on Saturday, 27 February 2010, at 03:34, having a magnitude of 8.8 on the moment magnitude scale, with intense shaking lasting for about three minutes.
The earthquake triggered a tsunami which devastated several coastal towns in south-central Chile and damaged the port at Talcahuano. The wave caused minor damage in the San Diego area of California and in the Tōhoku region of Japan, where damage to the fisheries business was estimated at ¥6.26 billion (US$66.7 million).
9. 1762 Arakan Earthquake (≤ 8.8 Mw)
The 1762 Arakan earthquake occurred at about 17:00 on April 2, with an epicentre somewhere on the coast from Chittagong (modern Bangladesh) to Arakan in modern Burma. It had an estimated magnitude of as high as 8.8 on the moment magnitude scale and a maximum estimated intensity of XI (Extreme) on the Mercalli intensity scale. It triggered a local tsunami in the Bay of Bengal.
10. 1707 Hōei Earthquake (8.7-9.3 Mw)
The 1707 Hōei earthquake, which occurred at 14:00 on October 28, 1707, was the largest earthquake in Japanese history until the 2011 Tōhoku earthquake surpassed it.
The earthquake, and the resulting destructive tsunami, caused more than 5,000 casualties.
11. 1700 Cascadia Earthquake (8.7–9.2 Mw)
The 1700 Cascadia earthquake occurred along the Cascadia subduction zone on January 26 with an estimated moment magnitude of 8.7–9.2. The megathrust earthquake involved the Juan de Fuca Plate that underlies the Pacific Ocean, from mid-Vancouver Island in British Columbia, Canada, south along the Pacific Northwest coast as far as northern California, USA. The length of the fault rupture was about 1,000 kilometres (620 miles) with an average slip of 20 metres (66 feet).
12. 1755 Lisbon Earthquake (8.5–9.0 Mw)
The 1755 Lisbon earthquake, also known as the Great Lisbon Earthquake, occurred in the Kingdom of Portugal on Saturday, 1 November 1755, the holiday of All Saints’ Day, at around 09:40.
In combination with subsequent fires and a tsunami, the earthquake almost totally destroyed Lisbon and adjoining areas.
Estimates place the death toll in Lisbon alone between 10,000 and 100,000 people, making it one of the deadliest earthquakes in history.
Shocks from the earthquake were felt throughout Europe as far as Finland and North Africa, and according to some sources even in Greenland and in the Caribbean. Tsunamis as tall as 20 metres (66 feet) swept the coast of North Africa, and struck Martinique and Barbados across the Atlantic.
Source – Wikipedia