The Cascadia subduction zone is a 960 km (600 mi) fault at a convergent plate boundary, about 110–160 km (70–100 mi) off the Pacific coast, that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is capable of producing 9.0+ magnitude earthquakes and tsunamis that could reach 30 m (98 ft). The Oregon Department of Emergency Management estimates shaking would last 5–7 minutes along the coast, with strength and intensity decreasing further from the epicenter. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, and Gorda plates move to the east and slide below the much larger mostly continental North American Plate. The zone varies in width and lies offshore beginning near Cape Mendocino, Northern California, passing through Oregon and Washington, and terminating at about Vancouver Island in British Columbia.
The 1976 Tangshan earthquake was a 7.6 earthquake that hit the region around Tangshan, Hebei, China, at 3:42 a.m. on 28 July 1976. The maximum intensity of the earthquake was XI (Extreme) on the Mercalli scale. In minutes, 85 percent of the buildings in Tangshan collapsed or were rendered unusable, all services failed, and most of the highway and railway bridges collapsed or were seriously damaged. The official report claimed 242,769 deaths and 164,851 serious injuries in Tangshan, but when taken into account the missing, the injured who later died and the deaths in nearby Beijing and Tianjin, scholars accepted at least 300,000 died, making it one of the deadliest earthquakes in recorded history and worst disasters in China by death toll.
The 1970 Ancash earthquake occurred on 31 May off the coast of Peru in the Pacific Ocean at . Combined with a resultant landslide, it is the most catastrophic natural disaster in the history of Peru. Due to the large amounts of snow and ice included in the landslide that caused an estimated 66,000-70,000 casualties, it is also considered to be the world's deadliest avalanche.
The 1950 Assam–Tibet earthquake, also known as the Assam earthquake, occurred on 15 August and had a moment magnitude of 8.7. The epicentre was located in the Mishmi Hills. It is the strongest earthquake ever recorded on land and is tied with the 2012 Indian Ocean Earthquakes as the strongest Strike-slip earthquake to date.
The 1138 Aleppo earthquake was among the deadliest earthquakes in history. Its name was taken from the city of Aleppo, in northern Syria, where the most casualties were sustained. The earthquake also caused damage and chaos to many other places in the area around Aleppo. The quake occurred on 11 October 1138 and was preceded by a smaller quake on the 10th. It is frequently listed as the third deadliest earthquake in history, following on from the Shensi and Tangshan earthquakes in China. However, the figure of 230,000 deaths reported by Ibn Taghribirdi in the fifteenth century is most likely based on a historical conflation of this earthquake with earthquakes in November 1137 on the Jazira plain and the large seismic event of 30 September 1139 in the Transcaucasian city of Ganja.
The 1918 San Fermín earthquake, also known as the Puerto Rico earthquake of 1918, struck the island of Puerto Rico at on October 11. The earthquake measured 7.1 on the moment magnitude scale and IX (Violent) on the Mercalli intensity scale. The mainshock epicenter occurred off the northwestern coast of the island, somewhere along the Puerto Rico Trench.
The 1959 Hebgen Lake earthquake occurred in the western United States on August 17 at 11:37 pm (MST) in southwestern Montana.
An earthquake occurred in the province of Sichuan, China at 14:28:01 China Standard Time on May 12, 2008. Measuring at 8.0 , the earthquake's epicenter was located 80 kilometres (50 mi) west-northwest of Chengdu, the provincial capital, with a focal depth of 19 km (12 mi). The earthquake ruptured the fault for over 240 km (150 mi), with surface displacements of several meters. The earthquake was also felt as far away as both Beijing and Shanghai—1,500 and 1,700 km away, respectively—where office buildings swayed with the tremor, as well as Bangkok, Thailand and Hanoi, Vietnam. Strong aftershocks, some exceeding 6 , continued to hit the area up to several months after the main shock, causing further casualties and damage. The earthquake also caused the largest number of geohazards ever recorded, including about 200,000 landslides and more than 800 quake lakes distributed over an area of 110,000 km2 (42,000 sq mi).
The 2003 Hokkaidō earthquake, scientifically named the 2003 Tokachi-Oki earthquake, occurred off the coast of Hokkaidō, Japan on 26 September at 04:50 local time. At a focal depth of 27 km (17 mi), this great undersea earthquake measured 8.3 on the moment magnitude scale, making it the most powerful earthquake of 2003, as well as one of the most intense earthquakes to hit Japan since modern record-keeping began in 1900.
The 1948 Fukui earthquake occurred in Fukui Prefecture, Japan. The magnitude 6.8 quake struck at 4:13:31 p.m.(JDT) on June 28, 1948. The quake's hypocenter was approximately 10 km north-northeast of Fukui, in the present-day neighborhood of Maruoka, Sakai City. The strongest shaking occurred in the city of Fukui, where it was recorded as 6 on the Japan Meteorological Agency seismic intensity scale.
The 1970 Tonghai earthquake occurred at with a moment magnitude of 7.1 and a maximum Mercalli intensity of X (Extreme). The strike-slip rupture originated on the Red River Fault, which had not experienced an earthquake above magnitude 7 since 1700, and affected Tonghai County, Yunnan province, China. At least 10,000 people were killed, making it one of the deadliest in its decade. The tremor caused between US$5 and $25 million in damage, felt over an area of 8,781 km2 (3,390 sq mi). In Hanoi, North Vietnam, almost 483 km (300 mi) from the epicenter, victims left their homes as the rupture rumbled through the city.
The 1980 El Asnam earthquake occurred on October 10 at with a moment magnitude of 7.1 and a maximum Mercalli intensity of X (Extreme). The shock occurred in the Algerian town of El Asnam. The shocks were felt over 550 km (340 mi) away, with the initial earthquake lasting 35 seconds. It was the largest earthquake in Algeria, and was followed three hours later by a magnitude 6.2 aftershock. The earthquake created about 42 km (26 mi) of surface rupture and had a vertical slip of up to 4.2 m (14 ft). No foreshocks were recorded. The earthquake was found to have occurred very close to the epicenter of the 1954 Chlef earthquake using joint epicenter determination techniques. It occurred at a previously unknown reverse fault.
The 1951 East Rift Valley earthquakes were a series of earthquakes which struck eastern Taiwan from 22 October 1951 to 5 December 1951, four of which registered at 7 or greater on the moment magnitude scale, the largest of those being magnitude 7.3 and 7.8 quakes on November 24. Altogether the quakes killed 85 people.
The 2010 Solomon Islands earthquake occurred with a moment magnitude of 7.1 on January 3 at 22:36:28 (UTC). A tsunami measuring approximately 10 feet affected some parts of the islands, while a maximum run-up height of 23.0 feet was recorded. The earthquake was the largest in a series of quakes to strike the Solomon Islands over the preceding days. The 7.1 mainshock was preceded by a 6.6 magnitude foreshock some 48 minutes previous. As many as 1,000 people were left homeless on the island of Rendova after the earthquake and tsunami destroyed approximately 200 homes.
The 1982 Flores earthquake struck the island of Flores in Indonesia on December 25. Registering a moment magnitude of 5.9, according to the International Seismological Centre, it created landslides and was reportedly accompanied by a tsunami. The earthquake killed thirteen people and left 390 injured, also destroying 1,875 houses and 121 other buildings. The villages of Layahong and Oyong Barang were damaged by seven seconds of shaking.
The 1941 Andaman Islands earthquake struck the Andaman Islands on June 26 with a magnitude of 7.7 to 8.1. Details of this event are poorly known as much of Southeast Asia was in the turmoil of World War II. The quake caused severe damage in the Andaman Islands. The tsunami it triggered was reported along the Andaman and Nicobar Islands, India and British Ceylon. There may have been damage and deaths in Bangladesh, Myanmar, and Thailand due to the tsunami.
The 2021 Kermadec Islands earthquakes were a series of earthquakes with magnitudes of 8.1 and 7.4 that occurred at 19:28:31 UTC on 4 March 2021. The epicentres were located southeast of Raoul Island in the Kermadec Islands, part of the New Zealand outlying islands. The main magnitude 8.1 earthquake was preceded by a magnitude 7.4 foreshock and followed by a magnitude 6.1 aftershock. A separate, unrelated magnitude 7.3 earthquake occurred off the coast of the North Island of New Zealand, approximately 900 km to the south, several hours before the main quakes. More than a dozen aftershocks exceeded magnitude 6.
The 2021 Assam earthquake struck 11 km away from Dhekiajuli, Assam, India at 07:51 (IST) on April 28, 2021 with a moment magnitude of 6.0 at 34.0 km (21.1 mi) depth. The quake struck with an epicenter 140 km north of the main city of Guwahati. It resulted in two fatalities and at least 12 injuries.
On 29 November, at 14:10 UTC, a magnitude 7.7 earthquake struck off the southern coast of Taliabu Island Regency in North Maluku, Indonesia. At least 41 people were killed on the nearby islands and a tsunami was triggered. Several hundred homes, buildings and offices were damaged or destroyed.
