View source for 1897 Assam earthquake

{{Use Indian English|date=July 2019}}
{{Use dmy dates|date=November 2019}}
{{Infobox earthquake
|title = 1897 Assam earthquake
|pre-1900 = yes
|local-date = {{Start-date|df=yes|12 June 1897}}
|local-time=17:15<ref name=NGDC/>
|map2 = {{Location map | India
 | label =
 | lat = 26
 | long = 91
 | mark = Bullseye1.png
 | marksize = 40
 | position = top
 | width = 250
 | float = right
 | caption =
 | relief = yes}}
|magnitude = 8.0 {{M|w|link=y}}<ref name=NGDC/> 
|depth = 
|location = {{coord|26|91|display=inline,title}}
|countries affected = [[India]]
|intensity = [[Mercalli intensity scale|X (''Extreme'')]]<ref name=NGDC/>
|tsunami =
|casualties = 1,542<ref name="E87">{{cite web|url=http://www.aasc.nic.in/course%20material/Disaster/documentation%20on%20past%20disasters.pdf|title=Documentation on past disasters, their impact, Measures taken, vulnerable areas in Assam.|access-date=29 April 2015|archive-url=https://web.archive.org/web/20150711124043/http://aasc.nic.in/course%20material/Disaster/documentation%20on%20past%20disasters.pdf|archive-date=11 July 2015|url-status=dead}}</ref>
}}
[[File:Oldham 1899 Map 1 memoirsofgeologi29geol 0547.jpg|thumb|265px|Map showing the epicentre and the areas affected by the 1897 earthquake<ref name=Report1899>{{cite journal|last=Oldham|first=R. D. |title=Report of the great earthquake of 12th June, 1897 |journal=Memoirs of the Geological Society of India |volume=29 |publisher=K. Paul, Trench, Trübner & co. |year=1899 |url=https://archive.org/details/memoirsofgeologi29geol }}</ref>]]
The '''Assam earthquake of 1897''' occurred on 12 June, 1897, in [[Assam]], [[India]] at 17:15 IST, and had an estimated [[moment magnitude scale|moment magnitude]] of 8.0. It resulted in approximate 1,542 human casualties and caused catastrophic damage to infrastructure. Damage from the earthquake extended into [[Calcutta]], where dozens of buildings were severely damaged, with some buildings partially collapsing. Trembles were felt across India, reaching as far as [[Ahmedabad]] and [[Peshawar]]. [[Seiches]] were also observed in [[Burma]].<ref name="E87"/>

==Earthquake==
The earthquake occurred on the SSW-dipping reverse Oldham fault that forms the northern edge of the [[Shillong Plateau]] within the [[Indian Plate]].<ref name=Bilham/><ref name=Hough>{{Cite journal|title=Revisiting the 1897 Shillong and 1905 Kangra earthquakes in northern India: Site response, Moho reflections and a triggered earthquake|last=Hough|first=S.E.|author-link=Susan Hough|last2=Bilham|first2=R.|last3=Ambraseys|first3=N.|author-link3=Nicholas Ambraseys|last4=Feldl|first4=N.|year=2005|journal=Current Science|volume=88|number=10|pages=1632–1638|url=https://pasadena.wr.usgs.gov/office/hough/curr-sci-05.pdf}}</ref> There was a minimum displacement on the main fault of 11&nbsp;m, although some calculations have placed this figure at as high as 16&nbsp;m, one of the greatest for any measured earthquake.<ref name=Bilham>{{cite journal |last=Bilham |first=Roger |last2=England |first2=Philip |title=Plateau 'pop-up' in the great 1897 Assam earthquake |journal=[[Nature (journal)|Nature]] |volume=410 |issue=6830 |pages=806–809 |year=2001 |doi=10.1038/35071057 |pmid=11298446|bibcode=2001Natur.410..806B }}</ref> The calculated area of slip extended 180&nbsp;km along strike and from 9–45&nbsp;km below the surface, indicating that the entire thickness of the [[Crust (geology)|crust]] was involved.

==Damage==
[[File:Oldham 1899 Plate 18 memoirsofgeologi29geol 0483.jpg|thumb|left|Government House in Shillong before and after the earthquake<ref name=Report1899/>]]Thought to have happened 32&nbsp;km underground, the earthquake left masonry buildings in ruins over 400,000&nbsp;km<sup>2</sup> area and was felt over 650,000&nbsp;km<sup>2</sup> from [[Burma]] to [[Delhi]]. Numerous buildings in the neighboring country of [[Bhutan]] were heavily damaged.<ref name=kalita>{{Cite web|title=The Great Assam Earthquake of 1897| first=Jugal|last= Kalita|author-link= Jugal Kalita |publisher=Assam Portal
|url=http://www.assam.org/content/great-assam-earthquake-1897}}</ref> Dozens of aftershocks were felt in and around the region with the last event being felt on 9 October 1897 at 01:40 [[Universal Time|UT]] in Calcutta.<ref name="E87"/>

The earthquake resulted in [[Shillong Plateau]] being thrust violently upwards by about 11&nbsp; meters. The fault was about 110&nbsp; km in length while the fault slip was about 18&nbsp;m (accuracy more or less by 7 m). At the epicenter, vertical acceleration is thought to have been above 1g force and surface velocity 3&nbsp;m/s.<ref>{{Cite journal | doi=10.1038/35071057| pmid=11298446| title=Plateau 'pop-up' in the great 1897 Assam earthquake| journal=Nature| volume=410| issue=6830| pages=806–809| year=2001| last1=Bilham| first1=Roger| last2=England| first2=Philip| bibcode=2001Natur.410..806B}}</ref>

[[File:Oldham 1899 Plate 07 memoirsofgeologi29geol 0453.jpg|thumb|Earthquake damage to a bridge on the [[East Bengal Railway]]<ref name=Report1899/>]]
In [[Shillong]], the earthquake damaged every stone house and half the houses built of wood.<ref name=Report1899/>{{rp|5}} The shock leveled the ground and resulted in 13 deaths. The fissure was also reported in the area. In Sohra [[Cherrapunji]], it resulted in a landslide, which led to 600 deaths.<ref name=town>{{Cite web | url=http://www.assam.org/content/great-assam-earthquake-1897 |title = The Great Assam Earthquake of 1897 &#124; Assam Portal}}</ref>
In [[Goalpara]], it resulted in waves from the river Brahmaputra, on which bank the town is situated, destroying the market.<ref name=town />
In [[Nalbari]], there were reported sightings of earth-waves and water waves.
In [[Guwahati]], the earthquake lasted for 3 minutes. the Brahmaputra river rose by 7.6&nbsp; ft. Damage was caused to [[Umananda Island]] temple and railway lines. 5 people died.<ref name=town />
In [[Nagaon]], every brick house was damaged, while traditional houses made of wood, with grass roofs, were bent. There were many small fissures/volcanos and the road was impassable for vehicles.<ref name=town />

In the [[Sylhet region]], shocks took place at 16:30, according to villagers living at the foot of the hills north of [[Sunamganj District|Sunamganj]]. There were 545 casualties. 55 in [[Sylhet town]], 178 in [[North Sylhet]], 287 in [[Sunamganj District|Sunamganj]], 7 in [[Habiganj District|Habiganj]], 8 in [[South Sylhet]] and 10 in [[Barak Valley|Karimganj]]. Many buildings collapsed and fissures and drowning furthered the amount of deaths. A woman in [[Sunamganj]] is said to have fell through a fissure whilst on a river with her husband. The husband tried to hold onto her hair but lost hold of her. The woman's body was not recovered from the [[crevasse]]. The [[Assam Bengal Railway]] was severely damaged.<ref>{{cite book|title=Assam District Gazetteers: Sylhet|volume=2|year=1905|location=[[Calcutta]]|author=B C Allen|publisher=[[Government of Assam]]|page=13–16|chapter=Physical Aspects |url=https://archive.org/details/in.ernet.dli.2015.463814/page/n21}}</ref><ref>{{cite journal |last1=Anderson |first1=Francis Philip |title=The effects of the earthquake in 1897 on the Shaistaganj division of the Assam-Bengal Railway |journal=Minutes of the Proceedings of the Institution of Civil Engineers |date=1900 |volume=141 |pages=258-261 |url=https://archive.org/details/anderson-1900-minutes-of-proceedings-of-the-institutio-141-1900}}</ref>{{r|Report1899|pages=295-298}}

[[Richard Dixon Oldham]], the Superintendent of the [[Geological Survey of India]], analysed seismic records of the earthquake, mainly from stations in Italy, and reported the first clear evidence of different type of [[seismic waves]], travelling through the earth on different paths and at different speeds.{{r|Report1899|pages=227-256}}

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

==References==
{{Reflist|refs=
<ref name=NGDC>{{citation|title=Significant Earthquake Database|url=https://www.ngdc.noaa.gov/nndc/struts/form?t=101650&s=1&d=1|author=National Geophysical Data Center / World Data Service (NGDC/WDS)|publisher=[[National Geophysical Data Center]], [[National Oceanic and Atmospheric Administration|NOAA]]|doi=10.7289/V5TD9V7K|year = 1972|type = Data Set}}</ref> 
}}

==Further reading==
* {{Cite journal|last=Ambraseys|first=N. N.|last2=Douglas|first2=J.|date=1 October 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|issn=0956-540X|bibcode=2004GeoJI.159..165A|doi-access=free}}
* {{cite journal |last=Gahalaut |first=V. K. |last2=Chander |first2=R. |title=A Rupture Model for the Great Earthquake of 1897, Northeast India |journal=Tectonophysics |volume=204 |issue=1–2 |year=1992 |pages=163–174 |doi=10.1016/0040-1951(92)90277-D |bibcode=1992Tectp.204..163G }}
* {{cite book |last=Lee |first=W. H. K. |first2=M. |last2=Meyers |first3=N. |last3=Shimazaki |title=Historical Seismograms and Earthquakes of the World |publisher=Academic Press |location=San Diego |year=1988 |isbn=978-0-12-440870-8 }}

==External links==
{{Commons category|1897 Assam earthquake}}
* [http://www.seismosoc.org/publications/SRL/SRL_79/srl_79-3_hs_esupp/ Tom LaTouche and the Great Assam Earthquake of 12 June 1897: Letters from the Epicenter] (with photographs of damage at Shillong, Rowmari and Calcutta, detailed field report with diagrams, and mapping of the epicentre)

{{Earthquakes in India}}
{{Himalayan earthquakes}}

{{DEFAULTSORT:Assam}}

{{#seo:
|keywords=1897 earthquakes, 1897 in India, June 1897 events, Disasters in Assam
|description=
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[[Category:Earthquakes in Assam|1897 Assam]]
[[Category:1897 earthquakes]]
[[Category:1897 in India]]
[[Category:Earthquakes in India|1897]]
[[Category:June 1897 events]]
[[Category:Disasters in Assam]]