Instruct: Given a question, retrieve relevant passages that can help answer the question.
Query: What was the magnitude of the last earthquake to hit the East Coast?
On August 23, 2011, a magnitude 5.8 earthquake hit the Piedmont region of the Commonwealth of Virginia, United States, at 1:51:04p.m. local time. The epicenter, in Louisa County, was 38mi (61km) northwest of Richmond and 5mi (8km) south-southwest of the town of Mineral. It was an intraplate earthquake with a maximum perceived intensity of VII (Very strong) on the Mercalli intensity scale. Several aftershocks, ranging up to 4.5 Mw in magnitude, occurred after the main tremor.
The 2003 Alabama earthquake took place on April 29 at 3:59 A.M. Central Daylight Time (local time when the event occurred) eight miles (13 km) east-northeast of Fort Payne, Alabama. The number of people who felt this quake was exceptionally high as the earthquake could be felt in 11 states across the East Coast and as far north as southern Indiana. The earthquake was strongly felt throughout metropolitan Atlanta. The Georgia Building Authority was called out to inspect the historic Georgia State Capitol in downtown Atlanta and other state-owned buildings, but found no problems. However, this is not out of the ordinary as earthquakes east of the Rocky Mountains can be felt several times the area felt on West Coast earthquakes. The earthquake was given a magnitude 4.6 on the moment magnitude scale by the USGS (other sources reported as high a magnitude as 4.9) and reports of the duration of the shaking range from 10 seconds to as long as 45 seconds. It is tied with a 1973 earthquake near Knoxville, Tennessee as the strongest earthquake ever to occur in the Eastern Tennessee Seismic Zone, which is the second most active seismic zone east of the Rocky Mountains, with the New Madrid Seismic Zone the most active.
Japan has had a long history of earthquake catastrophe and seismic activity. Earthquakes are the vibrations caused by rocks breaking under stress. The underground surface along which the rock breaks and moves is called a fault plane. Over time, stresses build beneath the earth’s surface. Occasionally, stress is released resulting in the sudden, and sometime disastrous shaking we call an earthquake. Earthquakes can cause shaking that could last seconds or minutes. Besides that, there may be several earthquakes over a period ranging from hours to weeks called aftershocks, and the magnitude of the following tremors will decrease with time. It is important to know the earthquake magnitude because it can be the clue if there will be any aftershocks. Because of that, magnitude can be measured on the Richter scale, invented by Charles F. Richter in 1934. The Richter magnitude is calculated from the amplitude of the largest seismic wave recorded for the earthquake. In the past twenty years, the most severe earthquake that occurred was in 2011 off the coast of Tohoku.
The earthquake's epicentre was west of Christchurch, near the town of Darfield. The hypocentre was at a shallow depth of 10 km. A foreshock of roughly magnitude 5.8 hit five seconds before the main quake, and strong aftershocks were reported, up to magnitude 6.3.
The initial quake lasted about 40 seconds, and was felt widely across the South Island, and in the North Island as far north as New Plymouth. As the epicentre was on land away from the coast, no tsunami occurred.
The 2017 Surigao earthquake occurred on February 10, 2017 at 10:03 PM (PST), with a surface wave magnitude of 6.7 off the coast of Surigao del Norte in the Philippines. According to the PHIVOLCS Earthquake Intensity Scale the earthquake was an Intensity VII ("Destructive") earthquake at maximum. In the past Surigao province has been hit by a magnitude 7.2 tremor in both 1879 and 1893.
On March 28, 1964, Whittier suffered over $10 million worth of damage in what became known as the Good Friday earthquake. As of 2019, the earthquake remains the largest U.S. earthquake, measuring 9.2 on the moment magnitude scale, and having caused tsunamis along the West Coast of the U.S. The tsunami that hit Whittier reached a height of 13 m (43 ft) and killed 13 people.
The 2008 Iceland earthquake was a doublet earthquake that struck on May 29 at 15:46 UTC in southwestern Iceland. The recorded magnitudes of the two main quakes were 5.9 and 5.8 , respectively, giving a composite magnitude of 6.1. There were no human fatalities, but 30 injuries were reported and a number of sheep were killed. The epicenter of the earthquake was between the towns of Hveragerði and Selfoss, about east-southeast of the capital, Reykjavík. It was the strongest earthquake to hit Iceland since the summer of 2000.
The first earthquake hit at 21:17 hours local time on April 24, 1957 and lasted 25 seconds having a magnitude of 7.1 on the moment magnitude scale; a stronger second quake occurred at 04:26 hours on April 25; this one lasted for 60 seconds and had a magnitude of 7.3. The earthquakes also shook many locations around Fethye, the epicenter, including Isparta, Burdur, Tefenni, Acıpayam, Denizli, Nazilli, Aydın, Yatağan, Milas, Bodrum, Ödemiş, Muğla, Marmaris, Köyceğiz, Kaş and Finike as well as the Greek islands of Kos, Symi and Rhodes.
The 1931 Hawke's Bay earthquake, also known as the Napier earthquake, occurred in New Zealand at 10:47 am on 3 February, killing 256, injuring thousands and devastating the Hawke's Bay region. It remains New Zealand's deadliest natural disaster. Centred 15 km north of Napier, it lasted for two and a half minutes and measured magnitude 7.8 
(magnitude 7.9 ). There were 525 aftershocks recorded in the following two weeks, with 597 being recorded by the end of February. The main shock could be felt in much of New Zealand, with reliable reports coming in from as far south as Timaru, on the east coast of the South Island.
The region of Zarand is close to an active fault, known as the Kuhbanan fault in the north east of the city. Its trend is northwest-southeast and its length is 160 km. Zarand has been hit by several quakes in the last 70 years, with the oldest recorded one going back to 1933. On December 21, 1977, the area was hit by a 6.2-magnitude earthquake leaving 521 dead and 3 villages completely destroyed. On December 26, 2003, another devastating earthquake happened in Bam, 200 km southwest of Zarand, which is in the same province.
This earthquake, like the previous earthquake of 20 May, was distinctly felt in Trentino Alto Adige. It was especially felt on the upper floors of buildings both in Trento and Bolzano, and created some concern among residents.
On 6 June at 06:08 local time, a magnitude 4.5 earthquake hit 50 km further east with an epicenter off the coast of Ravenna in Romagna at a depth 25.6 km.
The earthquake was felt strongly and distinctly in Ravenna and Rimini, then less in Pesaro and Ancona, and very slightly in the province of Modena, in areas already affected by earthquakes in recent days. This earthquake was generated by a fault other than that responsible for the earthquakes of 20 and 29 May in Emilia, although part of the same group of geological structures.
The 1886 Charleston earthquake occurred about 9:50 p.m. local time August 31 with an estimated moment magnitude of 6.9–7.3 and a maximum Mercalli intensity of X ("Extreme"). The intraplate earthquake caused 60 deaths and between $5 million and $6 million in damage to 2,000 buildings in the Southeastern United States. It is one of the most powerful and damaging earthquakes to hit the East Coast of the United States. Very little to no historical earthquake activity had occurred, which is unusual for any seismic area.
The USGS found that the farthest landslide from the 2011 Virginia earthquake was 150 miles (240km) from the epicenter. This is by far the greatest landslide distance recorded from any other earthquake of similar magnitude. Previous studies of worldwide earthquakes indicated that landslides occurred no farther than 36 miles (58km) from the epicenter of a magnitude 5.8 earthquake. The study suggested that the added information about East Coast earthquakes may prompt a revision of equations that predict ground shaking. "What makes this new study so unique is that it provides direct observational evidence from the largest earthquake to occur in more than 100 years in the eastern U.S. Now that we know more about the power of East Coast earthquakes, equations that predict ground shaking might need to be revised."
The submarine earthquake occurred at a focal depth of 49 km (30.4 mi) in the western Pacific Ocean on 7 April 2011 at 14:21 UTC, approximately 66 km (41 mi) east of Sendai. The quake was a direct result of thrust faulting on or near the subduction zone plate boundary between the Pacific and North American Plates. Initially estimated at a magnitude of 7.4, the tremor was felt in several areas near the east coast of Honshu as an aftershock of the 11 March magnitude 9.0 megathrust Tōhoku earthquake. The aftershock sequence of this event is ongoing since 11 March, and includes over 58 earthquakes of magnitude 6.0 or greater up until 7 April 2011, with only two others of magnitude 7.0 or greater.
The earthquake was reported as lasting between 6 and 7 minutes. It was followed by three strong aftershocks on 29 March, 30 March, and 3 April, all of which were probably of magnitude 7 or more, based on estimates of the reported intensities in the city of Oaxaca. It was felt over a wide area from Valladolid to Tehuantepec along the coast and as far inland as Tulancingo. The magnitude of this earthquake has been estimated from contemporary reports of seismic intensity. Analysis of other subduction interface earthquakes along this margin suggest that the extent of shaking of VIII or greater on the Mercalli intensity scale matches well with the rupture extent for each event. This suggests that the 1787 rupture extended for about 450 km along the coast, providing an estimate of magnitude 8.6, based on scaling against other similar earthquakes.
Since 1900, the only earthquakes recorded with a greater magnitude were the 1960 Great Chilean earthquake (Magnitude 9.5) and the 1964 Good Friday earthquake in Prince William Sound (Magnitude 9.2). The only other recorded earthquakes of magnitude 9.0 or greater were off Kamchatka, Russia, on 4 November 1952 (magnitude 9.0) and Tōhoku, Japan (magnitude 9.1) in March 2011. Each of these megathrust earthquakes also spawned tsunamis in the Pacific Ocean. However, in comparison to the 2004 Indian Ocean earthquake, the death toll from these earthquakes was significantly lower, primarily because of the lower population density along the coasts near affected areas, the much greater distances to more populated coasts, and the superior infrastructure and warning systems in MEDCs (More Economically Developed Countries) such as Japan.
Coastal Peru has a history of very large earthquakes. The August 15th shock originated near the source of two previous earthquakes, both in the magnitude 8 range, which occurred in 1908 and 1974. This earthquake is south of the source of a magnitude 8.2 earthquake that occurred in northern Peru on October 17, 1966, and north of a magnitude 8.4 earthquake that occurred in 2001 near Arequipa in southern Peru. The largest earthquake along the coast of Peru was a magnitude 9 that occurred in 1868 in Arica. It produced a tsunami that killed several thousand people along the Peruvian coast and also caused damage in Hawaii.
The 2014 Iquique earthquake struck off the coast of Chile on 1 April, with a moment magnitude of 8.2, at 20:46 local time (23:46 UTC). The epicenter of the earthquake was approximately northwest of Iquique. The mainshock was preceded by a number of moderate to large shocks and was followed by a large number of moderate to very large aftershocks, including a M7.7 event on 3 April. The megathrust earthquake triggered a tsunami of up to that hit Iquique at 21:05 local time (00:05 UTC, 2 April). Similar-sized tsunamis were also reported to have hit the coasts of Pisagua and Arica.
The 2007 Peru earthquake, which measured 8.0 on the moment magnitude scale, hit the central coast of Peru on August 15 at 23:40:57 UTC (18:40:57 local time) and lasted for about three minutes. The epicenter was located south-southeast of Lima at a depth of . The United States Geological Survey National Earthquake Information Center reported that it was a "Very strong" earthquake. The Peruvian government stated that 519 people were killed by the quake.
As of 16 March 2012 aftershocks continued, totaling 1887 events over magnitude 4.0; a regularly updated map showing all shocks of magnitude 4.5 and above near or off the east coast of Honshu in the last seven days showed over 20 events.
The earthquake prompted research that revealed that the farthest landslide from the epicenter was 150 miles (240km), by far the greatest landslide distance recorded from any other earthquake of similar magnitude. Previous studies of worldwide earthquakes indicated that landslides occurred no farther than 36 miles (58km) from the epicenter of a magnitude 5.8 earthquake. The Virginia earthquake study suggested that the added information about East Coast earthquakes may prompt a revision of equations that predict ground shaking.
It was hit by the 1944 Düzce earthquake, 1957 Abant earthquake, 1967 Adapazari earthquake, and in 1999 it was destroyed by the 17 August Izmit earthquake. It was demolished badly by another earthquake on 12 November 1999 at 18:57. The magnitude of the earthquake was 7.2 (Richter magnitude scale), lasted for 30 seconds, killing 845 people and injuring over 5,000. To quickly rebuild the earthquake damaged areas the Council of Ministers made Duzce the 81st province of Turkey in 1999.
Prehistoric earthquakes of similar size to the 1886 shock have occurred in coastal South Carolina at intervals of several centuries to several thousands of years. In recent decades, damaging earthquakes much smaller than that of 1886 have occurred every decade or two, most recently in 2014 (magnitude 4.1). Typically, smaller earthquakes are felt each year or two. East of the Rockies, an earthquake shakes the ground over an area up to ten times the area typically shaken by a similar magnitude earthquake on the west coast. For example, an eastern magnitude 4.0 earthquake typically can be felt at many locations as far as 100 km (60 mi) from where it occurred, and it might or might not cause damage near its source. An eastern magnitude 5.5 earthquake usually can be felt out to 500 km (300 mi) in most directions and can cause damage out to 40 km (25 miles).
Seismologists anticipated a very large quake would strike in the same place as the 1923 Great Kantō earthquake — in the Sagami Trough, southwest of Tokyo. The Japanese government had tracked plate movements since 1976 in preparation for the so-called Tokai earthquake, predicted to take place in that region. However, occurring as it did north east of Tokyo, the Tōhoku earthquake came as a surprise to seismologists. While the Japan Trench was known for creating large quakes, it had not been expected to generate quakes above an 8.0 magnitude. The Headquarters For Earthquake Research Promotion setup by Japanese government have then reassessed the long term risk of trench-type earthquakes around Japan, and it was announced in November 2011 that, combining with researches on 869 Sanriku earthquake, an earthquake similar to this one (with a magnitude of 8.4–9.0) would take place in the area between off the coast of Pacific side of the Northeast Japan in an average of every 600 years intervals (See also Seismicity of the Sanriku coast), and it is also assessed that a tsunami-earthquake with a tsunami magnitude scales (Mt) between 8.6 and 9.0 (Similar to 1896 Sanriku earthquake, the Mt for the 2011 Tōhoku earthquake is 9.1–9.4) will have a 30% chance to occur within 30 years.
The 1983 Sea of Japan earthquake or 1983 Nihonkai-Chubu earthquake occurred on May 26, 1983 at 11:59:57 local time (02:59:57 UTC). It had a magnitude of 7.8 on the moment magnitude scale. It occurred in the Sea of Japan, about 100 km west of the coast of Noshiro in Akita Prefecture, Japan. Out of the 104 fatalities, all but four were killed by the resulting tsunami, which struck communities along the coast, especially Aomori and Akita Prefectures and the east coast of Noto Peninsula. Images of the tsunami hitting the fishing harbor of Wajima on Noto Peninsula was broadcast on TV. The waves exceeded in some areas. Three of the fatalities were along the east coast of South Korea (whether North Korea was affected is not known). The tsunami also hit Okushiri Island, the site of a more deadly tsunami 10 years later.