1881 Nicobar Islands earthquake

Seismic event 1881 Nicobar Islands earthquake yes 31 December 1881 07:49 India 7.9 Mw 9.25 92.70 inline,title India, Andaman and Nicobar Islands yes VII none reported The 1881 Nicobar Islands earthquake occurred at about 07:49 local time (01:49 UTC) 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.Ortiz M. Bilham R. 2003 Source area and rupture parameters of the 31 December 1881 Mw = 7.9 Car Nicobar earthquake estimated from tsunamis recorded in the Bay of Bengal Journal of Geophysical Research American Geophysical Union 108 B4 2215 10.1029/2002JB001941 http://ciresweb.colorado.edu/~bilham/Andaman.pdf 2003JGRB..108.2215O Tectonic setting The Nicobar Islands are a series of volcanic islands that are part of an active volcanic arc, formed above the subduction zone where the Indo-Australian plate passes beneath the Burma plate. The convergence along this plate boundary is highly oblique, with the plate vector running at a low angle to the boundary. Most of the strike-slip component of the convergence is accommodated by the Great Sumatran fault, which passes northwards into the Andaman Sea spreading centre. This plate boundary has been the location of many historical megathrust earthquakes. The 1881 rupture area lies almost entirely within that for the w y 9.2 2004 Indian Ocean earthquake, while rupturing less than a third of its down-dip width. Damage The Andaman and Nicobar Islands suffered some damage, although the only masonry buildings affected were in Port Blair, including an infantry barrack and a chimney, both of which suffered severe cracking. On Car Nicobar, the coconut plantations and native huts were extensively damaged and sand volcanoes were observed. There were no reported casualties associated with either the earthquake or the subsequent tsunami.https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/2310 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 2 August 2022 10.7289/V5TD9V7K Characteristics Selected EMS-98 intensities Intensity Locations 7 Car Nicobar 6 Port Blair 5 Chennai 4 Banda Aceh, Colombo 3 Kolkata 2 Kathmandu, Mangalore Martin Szeliga 2010 Earthquake The earthquake was very widely felt with reports from many parts of mainland India, Burma and Sumatra, a total area of 2000000 sqmi km2. The rupture area, and therefore the magnitude, has been calculated by modelling the observed tsunami arrival times and heights. Two rupture areas have been identified. The larger, and more southerly, measured 150 km x 60 km dipping about 20° to the east with a displacement of 2.7 m ft and a smaller area to the north dipping 15° to the east with a displacement of 0.9 m ft on. The larger gives an estimated w y 7.9 event and the smaller a w 7.0 event.Bilham R. Engdahl R., Feldl N. & Satyabala S.P. 2005 Partial and Complete Rupture of the Indo-Andaman Plate Boundary 1847–2004 Seismological Research Letters 76 3 299–311 10.1785/gssrl.76.3.299 2005SeiRL..76..299B http://cires.colorado.edu/~bilham/IndonesiAndaman2004_files/AndamanSRL4Mar.pdf 20 November 2010 Tsunami The tsunami was recorded by eleven of a series of continuous tide gauges around the Bay of Bengal that had recently been deployed by the Great Trigonometric Survey of India. The ten gauges on the Indian mainland were synchronised using a telegraph to Madras (Chennai) time, while that at Port Blair was set by a chronometer linked to local time. The maximum recorded wave height was 1.22 m ft on at Nagapattinam. See also List of historical earthquakes List of tsunamis References A Catalog of Felt Intensity Data for 570 Earthquakes in India from 1636 to 2009 http://www.bssaonline.org/content/100/2/562.abstract S. Martin W. Szeliga 2010 Bulletin of the Seismological Society of America Seismological Society of America Electronic Supplement (table S2) 100 2 562–569 10.1785/0120080328 2010BuSSA.100..562M 2017-02-16 2016-11-12 https://web.archive.org/web/20161112172909/http://www.bssaonline.org/content/100/2/562.abstract dead subscription Category:Earthquakes in India Nicobar Islands Earthquake, 1881 Category:History of the Andaman and Nicobar Islands Category:1881 in India Category:19th-century tsunamis Category:1881 natural disasters Category:December 1881 Category:Tsunamis in India Category:Megathrust earthquakes in India Category:Tsunamis in Myanmar Category:Tsunamis in Thailand Category:1880s disasters in Asia Category:19th-century disasters in India