An earthquake – also called a quake, tremor, or temblor – is the shaking of the surface of Earth resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that 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. The word tremor is also used for non-earthquake seismic rumbling.
The 1811–1812 New Madrid earthquakes were a series of intense intraplate earthquakes beginning with an initial earthquake of moment magnitude 7.2–8.2 on December 16, 1811, followed by a moment magnitude 7.4 aftershock on the same day. Two additional earthquakes of similar magnitude followed in January and February 1812. They remain the most powerful earthquakes to hit the contiguous United States east of the Rocky Mountains in recorded history. The earthquakes, as well as the seismic zone of their occurrence, were named for the Mississippi River town of New Madrid, then part of the Louisiana Territory and now within the U.S. state of Missouri.
The 2006 Kamchatka earthquake occurred on . This shock had a moment magnitude of 7.6 and a maximum Mercalli intensity of X (Extreme). The hypocenter was located near the coast of Koryak Autonomous Okrug at an estimated depth of 22 km, as reported by the International Seismological Centre. This event caused damage in three villages and was followed by a number of large aftershocks. Two M6.6 earthquakes struck on April 29 at 16:58 UTC and again on May 22 at 11:12 UTC. These earthquakes caused no deaths; however, 40 people were reported injured.
ICEARRAY is an abbreviation for Icelandic Strong-motion Array. The ICEARRAY network is a seismic array of 14 strong-motion stations located within the South Iceland Seismic Zone. Each station consists of a seismograph situated in a protective housing. The stations are spread across a geographical area of approximately 3 km² in the town of Hveragerdi in south-western Iceland. Most of the units are located in the basements of residential buildings in Hveragerdi town centre, which is approximately 35 km southeast of Iceland's capital, Reykjavík. The ICEARRAY project is supported by the 6th Framework of the European Commission through the Marie Curie International Re-integration Grant, the Iceland Centre for Research and the University of Iceland Earthquake Engineering Research Centre.
The 2002 Denali earthquake occurred at 22:12:41 UTC November 3 with an epicenter 66 km ESE of Denali National Park, Alaska, United States. This 7.9 Mw earthquake was the largest recorded in the United States in 37 years. The shock was the strongest ever recorded in the interior of Alaska. Due to the remote location, there were no fatalities and only one injury.
The Brawley Seismic Zone (BSZ), also known as the Brawley fault zone, is a predominantly extensional tectonic zone that connects the southern terminus of the San Andreas Fault with the Imperial Fault in Southern California. The BSZ is named for the nearby town of Brawley in Imperial County, California, and the seismicity there is characterized by earthquake swarms.
A potent magnitude 6.6 Mw intraplate aftershock occurred at 17:16 JST (08:16 UTC) on 11 April, in the Hamadōri region of Fukushima, Japan. With a shallow focus of 13 km (8.1 mi), the earthquake was centred inland about 36 km (22 mi) west of Iwaki, causing widespread strong to locally severe shaking. It was one of many aftershocks to follow the 11 March Tōhoku earthquake, and the strongest to have its epicentre located inland.
The 2012 Shwebo earthquake occurred at 07:42 local time on 11 November in Myanmar. It had a magnitude of 6.8 on the moment magnitude scale and a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale. The epicenter was near the town of Male, 52 km NNE of the city of Shwebo, 64 km west of Mogok and 120 km north of Mandalay. Significant damage and possible casualties have been reported from near the epicenter, with up to 26 people dead and many more injured. Part of a bridge under construction fell into the Irrawaddy River near Shwebo and a gold mine collapsed at Sintku. An aftershock with a magnitude of 5.8 followed at 17:24 local time.
The geological deformation of Iceland is the way that the rocks of the island of Iceland are changing due to tectonic forces. The geological deformation explains the location of earthquakes, volcanoes, fissures, and the shape of the island. Iceland is the largest landmass (102,775 km²) situated on an oceanic ridge. It is an elevated plateau of the sea floor, situated at the crossing of the Mid-Atlantic Ridge and the Greenland-Iceland-Faeroe Ridge. It lies along the oceanic divergent plate boundary of North American Plate and Eurasian Plate. The western part of Iceland sits on the North American Plate and the eastern part sits on the Eurasian Plate. The Reykjanes Ridge of the Mid-Atlantic ridge system in this region crosses the island from southwest and connects to the Kolbeinsey Ridge in the northeast.
The 2020 Central Idaho earthquake occurred in the western United States on March 31, 2020, at 5:52 PM MDT, near Ruffneck Peak in the Sawtooth Mountains of central Idaho, 72 miles (116 km) northeast of Boise and 19 miles (31 km) northwest of Stanley. It had a magnitude of 6.5 and was felt with a maximum intensity of VIII.
The 2020 Sparta earthquake was a relatively uncommon intraplate earthquake that occurred near the small town of Sparta, North Carolina, on August 9, 2020 at 8:07 am local time. The earthquake had a moment magnitude of 5.1, and a shallow depth of 7.6 kilometers (4.7 mi). Shaking was reported throughout the Southern, Midwestern, and Northeastern United States. It was the strongest earthquake recorded in North Carolina in 104 years, the second-strongest in the state's history, and the largest to strike the East Coast since the 2011 Virginia earthquake.
In 1954, the state of Nevada was struck by a series of earthquakes that began with three magnitude 6.0+ events in July and August that preceded the Mw 7.1–7.3 mainshock and M 6.9 aftershock, both on December 12. All five earthquakes are among the largest in the state, and the largest since the Cedar Mountain earthquake of 1932 and Pleasant Valley event in 1915. The earthquake was felt throughout much of the western United States.
The Nemuro-Oki earthquake in scientific literature, occurred on June 17 at 12:55 local time. It struck with an epicenter just off the Nemuro Peninsula in northern Hokkaidō, Japan. It measured 7.8–7.9 on the moment magnitude scale (Mw ), 8.1 on the tsunami magnitude scale (Mt ) and 7.4 on the Japan Meteorological Agency magnitude scale (MJMA ).
The 2021 Maduo earthquake, also known as the 5.22 earthquake struck Madoi County in Qinghai Province, China on 22 May at 02:04 local time. The earthquake had a moment magnitude and surface-wave magnitude of 7.4. Highway bridges, roads and walls collapsed as a result of the earthquake. According to an anonymous source, at least 20 people were killed, 300 were injured, and 13 were missing. Officials stated that there were no deaths but 19 people sustained minor injuries. It was the strongest in China since 2008. It was assigned a maximum intensity of X in Machali, Maduo County on the China seismic intensity scale and Modified Mercalli intensity scale. This earthquake was preceded by another unrelated earthquake that occurred 5 hours earlier in Yunnan.
The 2020 Kashgar earthquake, also known as the Jiashi earthquake occurred on 19 January 2020 at 21:27:56 China Standard Time in Xinjiang Province, China. According to the United States Geological Survey, the earthquake had a moment magnitude of 6.0 and a surface wave magnitude of 6.4 according to the China Earthquake Network Center. It struck at a shallow depth of 5.6 km according to the USGS while the CENC has the figure at 16 km. Local emergency management agencies said the earthquake damaged more than 1,000 homes and businesses in the nearby populated towns and villages. One person is known to have died while two other children were injured.
The 1995 Menglian earthquake or 1995 Myanmar–China earthquake occurred on 12 July at 05:46:43 local time in the Myanmar–China border region. The earthquake had an epicenter on the Myanmar side of the border, located in the mountainous region of Shan State. It registered 7.3 on the Chinese surface wave magnitude scale (Ms ) and 6.8 on the moment magnitude scale (Mw ). With a maximum Mercalli intensity assigned at VIII, the quake killed eleven people and left another 136 injured. Over 100,000 homes in both countries were destroyed and 42,000 seriously damaged. Some damage to structures were also reported in Chiang Mai and Chiang Rai, Thailand. The low death toll from this earthquake was attributed to an early warning issued prior to it happening. Precursor events including foreshocks and some seismic anomalies led to an evacuation of the area before the mainshock struck. It is thought to be one of the few successfully predicted earthquakes in history.
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 2021 South Sandwich Islands earthquakes were a pair of powerful earthquakes, followed by many strong aftershocks which struck along the South Sandwich Trench in August 2021. The quakes measured 7.5 and 8.1 on the moment magnitude scale, according to the United States Geological Survey. The mainshock is tied with another event in 1929 as the largest earthquake ever recorded in this region, and is tied with the 2021 Kermadec Islands earthquake as the second largest earthquake of 2021.
The 2016 Alborian Sea earthquake struck offshore, north northeast of Al Hoceïma, Morocco in the Strait of Gibraltar on January 25 at 04:22:02 UTC, or roughly 05:22:02 West Africa Time. The strongest in the Alboran Sea, the earthquake measured 6.3–6.4 on the moment magnitude scale (Mw ) at a shallow hypocenter depth of 12 km (7.5 mi). Assigned a maximum Modified Mercalli scale intensity of VI (Strong), the earthquake caused one fatality, at least 30 injuries, and moderate damage in Morocco and Spain.
The 1979 Yapen earthquake occurred on September 12 at 05:17:51 UTC. It had an epicenter near the coast of Yapen Island in Irian Jaya, Indonesia. Measuring 7.5 on the moment magnitude scale and having a depth of 20 km (12 mi), it caused severe damage on the island. At least 115 were killed due to shaking and a moderate tsunami.
