An earthquake – also called a quake, tremor, or temblor – is the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume.
A tsunami is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and underwater explosions above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are in turn generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water from a large event.
The 1964 Alaskan earthquake, also known as the Great Alaskan earthquake and Good Friday earthquake, occurred at 5:36 PM AKST on Good Friday, March 27, 1964. Across south-central Alaska, ground fissures, collapsing structures, and tsunamis resulting from the earthquake caused about 131 deaths.
10.5 is a 2004 American disaster film directed by John Lafia which aired as a television miniseries in the United States on May 2, 2004, and May 3, 2004 on NBC. The plot focuses on a series of catastrophic earthquakes along the United States west coast, culminating in one measuring 10.5 on the Richter scale.
The Cascadia subduction zone is a 960 km (600 mi) fault at a convergent plate boundary, about 100–200 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 Aleutian Trench is an oceanic trench along a convergent plate boundary which runs along the southern coastline of Alaska and the Aleutian islands. The trench extends for 3,400 kilometres (2,100 mi) from a triple junction in the west with the Ulakhan Fault and the northern end of the Kuril–Kamchatka Trench, to a junction with the northern end of the Queen Charlotte Fault system in the east. It is classified as a "marginal trench" in the east as it runs along the margin of the continent. The subduction along the trench gives rise to the Aleutian Arc, a volcanic island arc, where it runs through the open sea west of the Alaska Peninsula. As a convergent plate boundary, the trench forms part of the boundary between two tectonic plates. Here, the Pacific plate is being subducted under the North American plate at a dip angle of nearly 45°. The rate of closure is 7.5 centimetres (3 in) per year.
The 1999 İzmit earthquake had a moment magnitude of 7.6 and struck Kocaeli Province, Turkey on 17 August. Between 17,127 and 18,373 people died as a result, and the damage was estimated at US$6.5 billion. It was named for the epicenter's proximity to the northwestern city of İzmit. The earthquake occurred at 03:01 local time at a shallow depth of 15 km (9.3 mi). A maximum Mercalli intensity of X (Extreme) was observed. The earthquake lasted for 37 seconds, causing seismic damage, and is widely remembered as one of the deadliest natural disasters in modern Turkish history.
The 1976 Moro Gulf earthquake and tsunami occurred on near the islands of Mindanao and Sulu, in the Philippines. It measured 8.0 on the moment magnitude scale occurring at a depth of 20 km (12 mi). The earthquake was accompanied by a destructive tsunami that resulted in a majority of the estimated 5,000 to 8,000 fatalities. It was the deadliest and strongest earthquake in the Philippines in 58 years since the 1918 Celebes Sea earthquake.
Striking southern Italy on 8 September, the 1905 Calabria earthquake had a moment magnitude of 7.2 and a maximum Mercalli intensity of XI (Extreme). The first major earthquake of the 20th century, it severely damaged parts of Lipari, Messina Province and a large area between Cosenza and Nicotera and killed between 557 and 2,500 people.
The 1896 Sanriku earthquake was one of the most destructive seismic events in Japanese history. The 8.5 magnitude earthquake occurred at 19:32 on June 15, 1896, approximately 166 kilometres (103 mi) off the coast of Iwate Prefecture, Honshu. It resulted in two tsunami waves which destroyed about 9,000 homes and caused at least 22,000 deaths. The waves reached a then-record height of 38.2 metres (125 ft); this would remain the highest on record until waves from the 2011 Tōhoku earthquake exceeded that height by more than 2 metres.
A tectonic weapon is a hypothetical device or system which could trigger earthquakes, volcanic eruptions, or other seismic events in specified locations by interfering with the Earth's natural geological processes. It was defined in 1992 by Aleksey Vsevolodovich Nikolayev, corresponding member of the Russian Academy of Sciences: "A tectonic or seismic weapon would be the use of the accumulated tectonic energy of the Earth's deeper layers to induce a destructive earthquake". He added "to set oneself the objective of inducing an earthquake is extremely doubtful." Though no such device is known to have been built, tectonic weapons have occasionally appeared as plot devices in works of fiction.
On 11 March 2011, at 14:46 JST, a 9.0–9.1 undersea megathrust earthquake occurred in the Pacific Ocean, 72 km (45 mi) east of the Oshika Peninsula of the Tōhoku region. It lasted approximately six minutes and caused a tsunami. It is sometimes known in Japan as the "Great East Japan Earthquake", among other names. The disaster is often referred to by its numerical date, 3.11.
Diablo Canyon (Nuclear) Power Plant, located in San Luis Obispo County California, was originally designed to withstand a 6.75 magnitude earthquake from four faults, including the nearby San Andreas Fault and Hosgri Fault, but was later upgraded to withstand a 7.5 magnitude quake. It has redundant seismic monitoring and a safety system designed to shut it down promptly in the event of significant ground motion.
At 02:10 PM local time (UTC-5) on 28 January 2020, an earthquake with a magnitude of 7.7 struck the north side of the Cayman Trough, north of Jamaica and west of the southern tip of Cuba, with the epicenter being 80 miles (130 km) east-southeast of Cayman Brac, Cayman Islands, and 83 miles (134 km) north of Montego Bay, Jamaica. Schools in Jamaica, as well as corporate and public buildings in Miami, were evacuated after shaking was experienced in parts of the U.S. state of Florida, a region not typically thought of in-relation to seismic activity. Light shaking was also reported on the Yucatán Peninsula in Mexico. The quake was the largest seismic event in the Caribbean since 1946. A tsunami warning for the Caribbean Sea was initially issued by the Pacific Tsunami Warning Center, later being withdrawn.
On January 1, 1996, at 4:05 p.m. Central Indonesia Time, an earthquake with an epicenter in the Makassar Strait struck north of Minahasa on the island of Sulawesi, Indonesia. The earthquake measured 7.9 on the moment magnitude scale and was centered off Tolitoli Regency in Central Sulawesi, or 25 km from the Tonggolobibi village. A tsunami of 2–4 m (6.6–13.1 ft) was triggered by this earthquake as a result. At least 350 buildings were badly damaged, nine people died and 63 people were injured.
An earthquake occurred off the coast of the Alaska Peninsula on July 28, 2021, at 10:15 p.m. local time. The large megathrust earthquake had a moment magnitude of 8.2 according to the United States Geological Survey (USGS). A tsunami warning was issued by the National Oceanic and Atmospheric Administration (NOAA) but later cancelled. The mainshock was followed by a number of aftershocks, including three that were of magnitude 5.9, 6.1 and 6.9 respectively.
The 1657 Concepción earthquake occurred on March 15 at 20:00 local time off the coast of Concepción, Biobío Region in the Spanish Empire. The earthquake caused severe damage along the coast, and generated a large tsunami in the Bay of Concepción. At least 40 people were killed, the majority due to drowning from the tsunami. The town of Concepción was the hardest hit, with the earthquake and tsunami totally destroying it.
The southern margin of the Gulf of Corinth was struck by a major earthquake on 26 December 1861 at 08:28 a.m. local time. It had an estimated magnitude in the range 6.6–6.7 and a maximum felt intensity of IX (destructive) on the European macroseismic scale (EMS). It caused widespread damage on both sides of the Gulf and led to up to 20 deaths and a further 126 people being injured, 18 of them seriously. A series of tsunami waves were reported, with a maximum run-up of 2.1 m.
