1762 Arakan earthquake

Earthquake in Bangladesh and Myanmar February 2026 1762 Arakan earthquake yes 2 April 1762 17:00 Bay of Bengal 8.5–8.8 w y 22.0 92.0 inline,title Chittagong and Arakan 11 Yes 200+ en-UK Megathrust 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.Mondal Dhiman R. McHugh Cecilia M. Mortlock Richard A. Steckler Michael S. Mustaque Sharif Akhter Syed Humayun Microatolls document the 1762 and prior earthquakes along the southeast coast of Bangladesh Tectonophysics October 2018 745 196–213 10.1016/j.tecto.2018.07.020 2018Tectp.745..196M 53578945 free 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 the course of the Brahmaputra River from east of Dhaka (Old Brahmaputra River) to 150 km to the west via the Jamuna River.http://www.aljazeera.com/news/2017/08/flooding-concerns-return-northeastern-india-170812072447986.html Flooding concerns return to northeastern India Al Jazeera 12 August 2017 Tectonic setting 190px|thumb|left|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 strikes parallel to the plate vector runs along the Western Burma Scarp, which 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. The presence of active subduction along the eastern margin of the Bay of Bengal is disputed.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 10.1016/j.margeo.2009.07.015 2009MGeol.266..143MKundu B. Gahalaut V.K. 2012 Earthquake occurrence processes in the Indo-Burmese wedge and Sagaing fault region Tectonophysics 524–525 135–146 10.1016/j.tecto.2011.12.031 2012Tectp.524..135K 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 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 extent combined with an estimated displacement of ten metres gives a maximum estimated magnitude of 8.8 on the moment magnitude scale.Cummins P.R. 2007 The potential for giant tsunamigenic earthquakes in the northern Bay of Bengal Nature 449 7158 75–78 10.1038/nature06088 2007Natur.449...75C 17805292 4425148 More recent research suggested a shorter rupture measuring 500 km, which combined with an estimated displacement of 9 to 16 meters gives an estimated magnitude of 8.5 on the moment magnitude scale.Wang Yu 2013 Earthquake Geology of Myanmar Ph.D. California Institute of Technology 10.7907/XWW2-9P26 https://thesis.library.caltech.edu/7853/ 3 May 2025 16 April 2023 https://web.archive.org/web/20250503063241/https://thesis.library.caltech.edu/7853/ dead 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. 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 during that earthquake. A repeat period of about 500 to 700 years was suggested for earthquakes similar to that in 1762. Tsunami A tsunami was reported along the northeastern coast of the Bay of Bengal and at Dhaka and Kolkata.https://www.ngdc.noaa.gov/hazel/view/hazards/tsunami/event-more-info/471 Tsunami Event Information National Geophysical Data Center / World Data Service: NCEI/WDS Global Historical Tsunami Database. NOAA National Centers for Environmental Information NOAA National Centers for Environmental Information 15 April 2022 10.7289/V5PN93H7 This is regarded as a local tsunami, as no effects were recorded on the western side of the bay. 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.Verelst Harry 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 https://books.google.com/books?id=Wn5bAAAAQAAJ&pg=PA265 27 March 2012 10.1098/rstl.1763.0043 free subscription An area of about 60 sqmi sqkm 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.https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/1368 Significant Earthquake Information National Geophysical Data Center / World Data Service (NGDC/WDS): NCEI/WDS Global Significant Earthquake Database. NOAA National Centers for Environmental Information 1972 NOAA National Centers for Environmental Information 15 April 2022 10.7289/V5TD9V7K See also List of historical earthquakes List of earthquakes in Myanmar List of earthquakes in Bangladesh References Further reading Gupta H. Harsh Gupta Gahalaut V. Is the Northern Bay of Bengal Tsunamigenic? Bulletin of the Seismological Society of America 99 6 2009 0037-1106 10.1785/0120080379 3496–3501 2009BuSSA..99.3496G collapsed Category:Earthquakes in Bangladesh Category:Earthquakes in Myanmar Category:1760s earthquakes Category:18th-century tsunamis Category:1762 disasters Category:1762 in Asia Category:18th century in Burma Category:Tsunamis in Myanmar