View source for 1819 Rann of Kutch earthquake

{{Short description|Earthquake and tsunami in Gujarat, India}}
{{Infobox earthquake
|title= 1819 Rann of Kutch earthquake
|pre-1900 = yes
|local-date= {{Start date text|16 June 1819}}
|local-time = 18:45 to 18:50
|map2 = {{Location map | India |relief=1
 | label=
 | lat=23.0
 | long=71.0
 | mark=Bullseye1.png
 | marksize=40
 | position=top
 | width= 250
 | float=right
 | caption=}}
|magnitude = 7.7–8.2 [[Moment magnitude scale|M<sub>w</sub>]]
|depth= 
|intensity= {{MMI|XI}}<ref name="NGDC">{{citation|url=https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/1642|title=Significant Earthquake Information|last=National Geophysical Data Center / World Data Service (NGDC/WDS): NCEI/WDS Global Significant Earthquake Database. NOAA National Centers for Environmental Information|year=1972 |publisher=NOAA National Centers for Environmental Information |author-link=National Geophysical Data Center|accessdate=30 July 2022|doi=10.7289/V5TD9V7K}}</ref>
|location={{coord|23.0|71.0|display=inline,title}}
|countries affected = [[India]], [[Gujarat]]
|tsunami = local
|casualties = >1,543<ref name="Martin"/>
}}
[[File:Kachchh Area.png|thumb|260px|Satellite photo showing location of the Allah Bund and Lake Sindri]]
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.<ref name="Martin"/> The [[earthquake]] caused an area of subsidence that formed the Sindri Lake and a local zone of uplift to the north about {{convert|80|km|abbr=on}} long, {{convert|6|km|abbr=on}} wide and {{convert|6|m|abbr=on}} high that dammed the Koree / Kori / Puran / [[Nara Canal|Nara river]]. This natural dam was known as the Allah Bund ("Dam of God").

==Tectonic setting==
The [[Kutch District]] of modern-day [[Gujarat]] lies on the [[Indian plate]], {{convert|300|–|400|km|abbr=on}} southeast of the plate boundary between the Indian plate and the [[Eurasian plate]], but the current tectonics is still governed by the effects of the continuing [[continental collision]] along this boundary. During the break-up of [[Gondwana]] in the [[Jurassic]] period, this area was affected by rifting with a roughly west–east trend. During the collision with Eurasia the area has undergone shortening, involving both reactivation of the original rift faults and the development of new low-angle [[thrust fault]]s. The related folding has formed a series of ranges, particularly in central Kutch. The [[focal mechanism]] of most earthquakes is consistent with reverse faulting on reactivated rift faults. The [[2001 Gujarat earthquake]] was caused by movement on a previously unknown south-dipping fault, trending parallel to the inferred rift structures.<ref name="Bodin">{{cite journal|last=Bodin|first=P.|author2=Horton S.|year=2004|title=Source Parameters and Tectonic Implications of Aftershocks of the Mw 7.6 Bhuj Earthquake of 26 January 2001|journal=Bulletin of the Seismological Society of America|volume=94|issue=3|pages=818–827|url=http://www.ceri.memphis.edu/people/shorton/AFTERSHOCK/bhuj1.pdf|accessdate=2 April 2012|bibcode = 2004BuSSA..94..818B |doi = 10.1785/0120030176 }}</ref>

==Earthquake==
The earthquake lasted for two to three minutes. It was felt over an enormous area, from [[Chennai]] to [[Kolkata]] in the east, as far north as [[Kathmandu]] and as far west as [[Balochistan]]. The main shock was followed by prolonged [[aftershock]] activity, with major earthquakes continuing for at least 50 years, including one with estimated magnitude of more than 6.5 in 1846.<ref name="Bilham"/>

Maximum displacement during the earthquake is estimated at {{convert|12|m|abbr=on}}, based on the height of the bund and the amount of subsidence to the south. Combined with a lateral extent of at least {{convert|80|km|abbr=on}}, this gives an estimated [[moment magnitude scale|moment magnitude]]<!-- Note that Bilham actually says Local Magnitude (Richter) in the text on page 16 (page 307 in the published paper) but later refers to it as a moment magnitude in the conclusions "The geometric moment magnitude of the event is estimated as M=7.7±2" - the equations given on page 16 are those used to calculate moment magnitude from the throw, fault area and rigidity modulus.--> of 7.7±0.2. This matches well with magnitudes estimated using both the total felt area and the area of VIII intensity.<ref name="Bilham"/> Other estimates based on intensity measurements give magnitudes as high as 8.2.<ref name="Ambraseys">{{cite journal|last=Ambraseys|first=N.N.|author2=Douglas J.|year=2004|title=Magnitude calibration of north Indian earthquakes|journal=[[Geophysical Journal International]]|volume=159|issue=1|pages=165–206|doi=10.1111/j.1365-246X.2004.02323.x|bibcode = 2004GeoJI.159..165A |doi-access=free}}</ref>

Modelling of the surface deformation indicates that the fault that slipped during the earthquake dipped to the north at between about 50°–67°. As faults that dip in excess of 50° are normally unfavourable for slip, it has been suggested that there was relatively high pore-fluid pressure developed at depth to allow this displacement to occur.<ref name="Bilham"/> There is evidence that the Indus river shifted westwards after this earthquake.<ref>{{cite web|url=https://www.indiatoday.in/india/west/story/indus-river-re-enters-india-145091-2011-11-06 |title=Indus re-enters India after two centuries, feeds Little Rann, Nal Sarovar |work=India Today|date=7 November 2011 |access-date=2011-11-07}}</ref>

===Allah Bund===
[[File:Gujarat Geological map.jpg|thumb|1854 map of the region by [[George Bellas Greenough]]]]
The most obvious topographic effect of this earthquake was the formation of a ridge about {{convert|6|m|abbr=on}} high, extending for 80&nbsp;km (possibly as much as {{convert|150|km|abbr=on}}) that formed a natural dam across the Puram or Kori River.<ref>{{cite web|url= http://www.akshardhool.com/2013/09/two-disasters-that-changed-indias-south.html|title=Two disasters that defined India's south-west border with Pakistan for ever|accessdate=22 December 2015}}</ref><ref>{{cite web|url= http://floodobservatory.colorado.edu/Publications/MetamorphosisofIndus.pdf|title=Anthropocene Metamorphosis of the Indus Delta and Lower Floodplain|accessdate=22 December 2015}}</ref> To distinguish it from the man-made dams that were common in the region, the uplifted area became known as the Allah Bund, or Dam of God.<ref name="Bilham"/> The mound produced had a markedly asymmetric geometry, with a shorter and steeper south-dipping margin, about 600&nbsp;m wide and a dip of 0.65°, and a broader north-dipping margin over 5&nbsp;km wide with a dip of only about 0.05°.<ref name="Bilham"/>

===Sindri Lake===
Sindri Lake, with a surface area of more than {{convert|1000|km2|abbr=on}}, was formed due to subsidence of up to {{convert|3|m|abbr=on}} south of the Allah Bund. Initially, the lake was cut off from the river (damming further upstream had stopped the flow) and was filled with seawater. On the western margin of the lake a small delta built out from the eastern part of the larger [[Indus River|Indus Delta]]. After 1826 the river broke through the artificial dam and eventually broke through the bund itself, causing the lake to become freshwater again.<ref name="Bilham"/>

===Later earthquakes===
The [[1956 Anjar earthquake]] was due to [[reverse fault]]ing, similar in type to that which is thought to have caused the 1819 Rann of Kutch earthquake.<ref name="Chung & Gao">{{cite journal | title=Source parameters of the Anjar earthquake of July 21, 1956, India, and its seismotectonic implications for the Kutch rift basin | author=Chung W.-Y. & Gao H. | journal=Tectonophysics | year=1995 | volume=242 | issue=3–4 | pages=281–292 | doi=10.1016/0040-1951(94)00203-L|bibcode = 1995Tectp.242..281C }}</ref>

Changes in stress caused by [[coulomb stress transfer]] due to the 1819 earthquake may have been sufficient to trigger the [[2001 Bhuj earthquake]] and other historic earthquakes that occurred in the region during the intervening period.<ref name="To">{{cite journal|last=To|first=A.|author2=Bürgmann R. & Ollitz F.|year=2004|title=Postseismic deformation and stress changes following the 1819 Rann of Kachchh, India earthquake: Was the 2001 Bhuj earthquake a triggered event? |journal=Geophysical Research Letters|volume=31|issue=13|pages=L13609|doi=10.1029/2004GL020220|bibcode = 2004GeoRL..3113609T |doi-access=free}}</ref>

==Tsunami==
There was a local tsunami that flooded the area known as the [[Great Rann of Kutch|Great Rann]] immediately after the earthquake. The [[Sindhri Fort|fort at Sindri]] was destroyed by the earthquake and then partly submerged by the tsunami, "forcing survivors to climb to the top of the ruins."<ref name="Bilham">{{cite book|last=Bilham|first=R.|title=Coastal tectonics|editor=Stewart I.S. & Vita-Finzi C.|publisher=[[Geological Society]]|location=London|year=1998|series=Special Publications|volume=146|pages=295–319|chapter=Slip parameters for the Rann of Kachchh, India, 16 June 1819 earthquake, quantified from contemporary accounts|isbn=9781862390249|chapter-url=http://cires.colorado.edu/~bilham/gif_images/1819article.pdf|accessdate=2 April 2012}}</ref>

==Damage==
The towns of [[Kothara, Kutch|Kothara]], [[Mothala, Gujarat|Mothala]], [[Naliya]] and [[Vinzan]] suffered particularly heavy damage. [[Anjar, India|Anjar]], [[Bhuj]], [[Lakhpat]], [[Mandvi]] and [[Tera, Kutch|Tera]] were also severely affected.<ref name="Martin">{{cite journal|url=http://www.seismosoc.org/publications/bssa_html/bssa_100-2/2008328-esupp/annotations.html |title=Electronic Supplement to A Catalog of Felt Intensity Data for 570 Earthquakes in India from 1636 to 2009 |journal=Bulletin of the Seismological Society of America |volume=100 |issue=2 |pages=562–569 |last=Martin |first=S. |author2=Szeliga W. |year=2010 |doi=10.1785/0120080328 |accessdate=2 April 2012 |url-status=dead |archiveurl=https://web.archive.org/web/20131211225650/http://www.seismosoc.org/publications/bssa_html/bssa_100-2/2008328-esupp/annotations.html |archivedate=11 December 2013 |bibcode=2010BuSSA.100..562M |url-access=subscription }}</ref> At least 1,543 people were killed in the larger towns; the number of casualties in smaller towns and villages is unknown. There was some degree of damage to buildings over most of [[Gujarat]], including the destruction of the "shaking minarets" of the [[Jama Masjid, Ahmedabad|Jama Masjid]] in [[Ahmedabad]]. At [[Jaisalmer]] in [[Rajasthan]], "at least 500 guests were smothered at a wedding feast".<ref name="Martin"/>

==See also==
* [[List of earthquakes in India]]
* [[List of historical earthquakes]]
* [[List of tsunamis]]

==References==
{{Reflist}}

{{Earthquakes in India}}

[[Category:Earthquakes in Gujarat|1819 Rann]]
[[Category:1819 earthquakes]]
[[Category:Kutch district]]
[[Category:19th century in Gujarat]]
[[Category:1819 in India]]
[[Category:History of Kutch]]
[[Category:Earthquakes in India|1819 Rann]]
[[Category:19th-century tsunamis]]
[[Category:June 1819]]
[[Category:1810s disasters in Asia]]
[[Category:19th-century disasters in India]]