1762 Arakan earthquake

1762 Arakan earthquake
Local date	2 April 1762
Local time	17:00
Magnitude	8.5–8.8 Mw
Epicentre	22°00′N92°00′E / 22.0°N 92.0°E
Areas affected	Bangladesh
Max. intensity	XI (Extreme)
Tsunami	Yes
Casualties	200+

Last updated December 17, 2023

The 1762 Arakan earthquake occurred at about 17:00 local time on 2 April, with an epicentre somewhere along the coast from Chittagong (modern Bangladesh) to Arakan in modern Myanmar.^[1] It had an estimated moment magnitude between 8.5 and 8.8 and a maximum estimated intensity of XI (Extreme). It triggered a local tsunami in the Bay of Bengal and caused at least 200 deaths. The earthquake was associated with major areas of both uplift and subsidence. It is also associated with a change in course of the Brahmaputra River to from east of Dhaka (Old Brahmaputra River) to 150 kilometres (93 mi) to the west via the Jamuna River.^[2]

Tectonic setting

Tectonic map of Myanmar with the oblique convergent boundary, the Arakan Trench Text6986-6.png — Tectonic map of Myanmar with the oblique convergent boundary, the Arakan Trench

The eastern part of Bangladesh and the southwestern part of Burma lie along the highly oblique convergent boundary between the Indian Plate and the Eurasian Plate. The degree to which this deformation is partitioned into zones of thrust tectonics (accommodating that part of the motion perpendicular to the boundary) and strike-slip tectonics (accommodating the northward movement of the Indian Plate) varies along the boundary. A pure strike-slip boundary that strike parallel to the plate vector runs along the Western Burma Scarp, that is replaced to the north by the Indo-Burmese Wedge fold and thrust belt, at the western edge of the boundary zone, and a series of major dextral (right lateral) strike-slip faults, particularly the Kabaw Fault and Sagaing Fault further to the east.^[3] The presence of active subduction along the eastern margin of the Bay of Bengal is disputed.^[3]^[4]

Earthquake

The earthquake lasted for about four minutes at Chittagong. The epicentre is not well-constrained and likely locations have varied from near Chittagong to along the Arakan coast. The extent of the rupture is uncertain but may have been as much as 700 km (430 mi) along the plate interface. This is based both on the extent of uplift, which was recorded along the coast of Burma from Foul Island to Ramree Island, and the area of subsidence around Chittagong, further north. The 700 km (430 mi) extent combined with an estimated displacement of ten metres gives a maximum estimated magnitude of 8.8 on the moment magnitude scale.^[5] More recent research suggested a shorter rupture measuring 500 km (310 mi), which combined with estimated displacement of 9 to 16 meters gives an estimated magnitude of 8.5 on the moment magnitude scale.^[6] Other workers have pointed out that neither the subsidence, which could be due to lateral spreading, nor the uplift, which is not unequivocally linked to the 1762 earthquake, necessarily provide a reasonable estimate for the size of this event and prefer to regard this as a magnitude 7–8 earthquake.^[4]

Studies of uplifted marine terraces along the Burmese coast have found evidence for three uplifts, the most recent of which is interpreted to be from the 1762 earthquake. The St. Martin's Island has been uplifted by 2–2.5 m (6 ft 7 in – 8 ft 2 in) during that earthquake.^[1] A repeat period of about 500 to 700 years was suggested for earthquakes similar to that in 1762.^[1]

Tsunami

A tsunami was reported along the northeastern coast of the Bay of Bengal and at Dhaka and Kolkata.^[7] This is regarded as a local tsunami, as no effects were recorded on the western side of the bay.^[4]

Damage

In Chittagong, it was reported that no buildings or walls built of brick had escaped either destruction or serious damage. The East India Company's factory inside the fort was so badly damaged that it could no longer be safely used.^[8] An area of about 60 square miles (160 km²) permanently subsided beneath the sea along the coast near Chittagong. At Bar Chara, just north of Cox's Bazar, the land sank and 200 people were killed. Chittagong was said to have "suffered severely" with soil liquefaction effects such as sand volcanoes and ground fissures.^[9]

Related Research Articles

The 1481 Rhodes earthquake occurred at 3:00 in the morning on 3 May. It triggered a small tsunami, which caused local flooding. There were an estimated 30,000 casualties. It was the largest of a series of earthquakes that affected Rhodes, starting on 15 March 1481, continuing until January 1482.

The 1303 Crete earthquake occurred at about dawn on 8 August. It had an estimated magnitude of about 8, a maximum intensity of IX (Violent) on the Mercalli intensity scale, and triggered a major tsunami that caused severe damage and loss of life on Crete and at Alexandria. It badly damaged the Lighthouse of Alexandria.

The 1498 Meiō earthquake occurred off the coast of Nankaidō, Japan, at about 08:00 local time on 20 September 1498. It had a magnitude estimated at 8.6 M_s and triggered a large tsunami. The death toll associated with this event is uncertain, but between 5,000 and 41,000 casualties were reported. The tsunami caused by the Meiō Nankaidō earthquake washed away the building housing the statue of the Great Buddha at Kōtoku-in in Kamakura, although the statue itself remained intact.

The 1881 Nicobar Islands earthquake occurred at about 07:49 local time on 31 December, with an epicentre beneath Car Nicobar. It occurred as two separate ruptures, the largest of which had an estimated magnitude of 7.9 on the moment magnitude scale and triggered a tsunami that was observed around the Bay of Bengal. It is probably the earliest earthquake for which rupture parameters have been estimated instrumentally.

The 1819 Rann of Kutch earthquake occurred at about 18:45 to 18:50 local time on 16 June 1819. It had an estimated magnitude ranging from 7.7 to 8.2 on the moment magnitude scale and a maximum perceived intensity of XI (Extreme) on the Mercalli intensity scale. It triggered a tsunami and caused at least 1,543 deaths. The earthquake caused an area of subsidence that formed the Sindri Lake and a local zone of uplift to the north about 80 km (50 mi) long, 6 km (3.7 mi) wide and 6 m (20 ft) high that dammed the Koree / Kori / Puran / Nara river. This natural dam was known as the Allah Bund.

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 1975 Bagan earthquake occurred on July 8 at 6:34 pm local time in Bagan, Myanmar. Many important stupas and temples were destroyed. The strongest intensity was felt in the towns of Nyaung-U, Pakokku, and Yesagyo, and in the Myaing townships on the confluence of the Ayeyawady River. Damage was also reported in Chauk and Natmauk townships. It had a magnitude of M_w 7.0.

The 1930 Bago (Pegu) earthquake, also known as the Swa earthquake struck Myanmar on 5 May. The moment magnitude (M_w ) 7.4 earthquake had a focal depth of 35 km (22 mi) and maximum Rossi–Forel intensity of IX. The earthquake was the result of rupture along a 131 km (81 mi) segment of the Sagaing Fault—a major strike-slip fault that runs through the country. Extensive damage was reported in the southern part of the country, particularly in Bago and Yangon, where buildings collapsed and fires erupted. At least 550, and possibly up to 7,000 people were killed. A moderate tsunami was generated along the Burmese coast which caused minor damage to ships and a port. It was felt for over 570,000 km² (220,000 sq mi) and as far as Shan State and Thailand. The mainshock was followed by many aftershocks; several were damaging; additional earthquakes occurred in July and December, killing dozens. The December earthquake was similarly sized which also occurred along the Sagaing Fault.

The 1839 Ava earthquake, also known as the Amarapura earthquake or Inwa earthquake, was a disastrous seismic event that struck central Burma on the morning of March 23. This earthquake with a moment magnitude as high as 8.3, was one of the biggest in the country since 1762. Shaking reached XI (Extreme) on the Modified Mercalli intensity scale, and was felt in Rangoon and Bhamo.

The 1988 Myanmar–India earthquake, also known as the Indo–Burma earthquake struck the Sagaing Region of Myanmar, about 30 kilometres (19 mi) from the border with India on 6 August at 7:06 am MMT with a moment magnitude (M_w ) of 7.3 or Richter magnitude (M_L ) of 7.5. At least five people were killed, more than 30 were injured, and another 30 were missing as a result. Serious damage was reported in India and Bangladesh, while some minor damage occurred in Myanmar. The earthquake was reportedly felt in the Soviet Union.

The western coast of West Sulawesi was struck by a major earthquake on 23 February 1969 at 00:36 UTC. It had a magnitude of 7.0 M_w and a maximum felt intensity of VIII on the Modified Mercalli intensity scale. It triggered a major tsunami that caused significant damage along the coast of the Makassar Strait. At least 64 people were killed, with possibly a further 600 deaths caused by the tsunami.

The 1761 Lisbon earthquake and its subsequent tsunami occurred in the north Atlantic Ocean and south of the Iberian Peninsula. This violent shock which struck just after noon on 31 March 1761, was felt across many parts of Western Europe. Its direct effects were even observed far north in Scotland and Amsterdam, and to the south in the Canary Islands of Spain. The estimated surface-wave magnitude 8.5 event was the largest in the region, and the most significant earthquake in Europe since the Great Lisbon earthquake of 1755.

The 1872 Amik (Antakya) earthquake occurred on April 3 with an epicenter within the Amik Valley in the Ottoman Empire. Earthquake had an estimated magnitude of M_w  7.0–7.2 or M_s  7.2 and maximum MSK 64 rating of XI (Catastrophic). Turkey and Syria were devastated by this earthquake, and the region lost at least 1,800 residents.

The 1933 Sumatra earthquake or Liwa earthquake occurred in West Lampung Regency, Lampung Province, Indonesia on June 25. The earthquake had an estimated surface-wave magnitude (M_s ) of 7.7 occurring at a shallow depth of 20 km. It had an epicenter onshore, devastating the city of Liwa. At least 76 people were reported killed, although the death toll may have been in the thousands. Aftershocks followed, including one which was strong enough to cause additional fatalities. The mainshock also triggered a nearby volcanic eruption two weeks later, killing some people.

The 1858 Prome earthquake occurred on August 24 at 15:38 local time in British Burma. The earthquake occurred with a magnitude of 7.6–8.3 on the moment magnitude scale. It had an epicenter in near the city of Pyay (Prome), Bago. The shock was felt with a maximum Modified Mercalli intensity of XI (Extreme) for about one minute. Severe damage was reported in Bago, and off the coast of Rakhine, an island sunk.

The 1867 Keelung earthquake occurred off the northern coast of Taiwan on the morning of December 18 with a magnitude of 7.0. It produced strong shaking that seriously damaged the cities of Keelung and Taipei. A tsunami, thought to be the only confirmed destructive of its kind in Taiwan, drowned hundreds and had a run-up exceeding 15 m (49 ft). The total death toll was estimated to be 580 while more than 100 were injured. It was followed by aftershocks that were felt on average ten times a day.

The Shōnai offshore earthquake occurred at around 14:00 on December 7, 1833. It struck with an epicenter in the Sea of Japan, off the coast of Yamagata Prefecture, Japan. A tsunami was triggered by the estimated M_JMA  7.5–7.7 earthquake. One hundred and fifty people were killed and there was severe damage in the prefecture.

The 1755 Meknes earthquake affected Morocco on 27 November 1755. The earthquake had a moment magnitude (M_w ) estimated at between 6.5 and 7.0. It devastated the cities of Fes and Meknes—killing at least 15,000 people in both cities.

The 1940 Shakotan earthquake occurred on August 2 at 00:08:22 JST with a moment magnitude (M_w ) of 7.5 and maximum JMA seismic intensity of Shindo 4. The shock had an epicenter off the coast of Hokkaido, Japan. Damage from the shock was comparatively light, but the accomanying tsunami was destructive. The tsunami caused 10 deaths and 24 injuries on Hokkaido, and destroyed homes and boats across the Sea of Japan. The highest tsunami waves were recorded at the coast of Russia while along the coast of Hokkaido, waves were about 2 m.

References

1 2 3 Mondal, Dhiman R.; McHugh, Cecilia M.; Mortlock, Richard A.; Steckler, Michael S.; Mustaque, Sharif; Akhter, Syed Humayun (October 2018). "Microatolls document the 1762 and prior earthquakes along the southeast coast of Bangladesh". Tectonophysics. 745: 196–213. Bibcode:2018Tectp.745..196M. doi: 10.1016/j.tecto.2018.07.020 . S2CID 53578945.
↑ "Flooding concerns return to northeastern India". Al Jazeera.
1 2 Maurin, T.; Rangin C. (2009). "Impact of the 90°E ridge at the Indo-Burmese subduction zone imaged from deep seismic reflection data". Marine Geology. 266 (1–4): 143–155. Bibcode:2009MGeol.266..143M. doi:10.1016/j.margeo.2009.07.015.
1 2 3 Kundu, B.; Gahalaut V.K. (2012). "Earthquake occurrence processes in the Indo-Burmese wedge and Sagaing fault region". Tectonophysics. 524–525: 135–146. Bibcode:2012Tectp.524..135K. doi:10.1016/j.tecto.2011.12.031.
↑ Cummins, P.R. (2007). "The potential for giant tsunamigenic earthquakes in the northern Bay of Bengal". Nature. 449 (7158): 75–78. Bibcode:2007Natur.449...75C. doi:10.1038/nature06088. PMID 17805292. S2CID 4425148.
↑ Wang, Yu (2013). Earthquake Geology of Myanmar (Ph.D.). California Institute of Technology. doi:10.7907/XWW2-9P26.
↑ National Geophysical Data Center / World Data Service: NCEI/WDS Global Historical Tsunami Database. NOAA National Centers for Environmental Information. "Tsunami Event Information". NOAA National Centers for Environmental Information. doi:10.7289/V5PN93H7 . Retrieved 15 April 2022.
↑ Verelst (1764). "An Account of the Earthquakes that have been felt in the Province of Islamabad, with the Damages attending them, from the 2d to the 19th of April, 1762". Philosophical Transactions of the Royal Society. 53: 265–269. doi: 10.1098/rstl.1763.0043 . Retrieved 27 March 2012.
↑ National Geophysical Data Center / World Data Service (NGDC/WDS): NCEI/WDS Global Significant Earthquake Database. NOAA National Centers for Environmental Information (1972). "Significant Earthquake Information". NOAA National Centers for Environmental Information. doi:10.7289/V5TD9V7K . Retrieved 15 April 2022.

v t e Earthquakes and plate tectonics in Myanmar
Pre-20th century	1762 Rahkine 1839 Innwa 1858 Prome
20th century	1912 Taunggyi 1930 Bago 1930 Pyu 1931 Myitkyina 1946 Sagaing 1950 Assam–Tibet 1956 Sagaing 1975 Bagan 1976 Yunnan 1988 Myanmar–India 1988 Lancang–Gengma 1995 Menglian 1997 Chittagong
21st century	2003 Taungdwingyi 2004 Indian Ocean 2009 Coco Islands 2011 Yingjiang 2011 Tarlay 2012 Thabeikkyin 2016 Imphal 2016 Chauk 2016 Kani
Fault zones and tectonic plates	Sagaing Fault Kyaukkyan Fault Three Pagodas Fault West Andaman Fault Kabaw Fault Sunda megathrust Main Himalayan Thrust Main Frontal Thrust Burma Plate Sunda Plate Indian Plate Eurasian Plate