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{{Short description|6.8 magnitude earthquake in India}} | |||
{{Use dmy dates|date=November 2019}} | {{Use dmy dates|date=November 2019}} | ||
{{Use Indian English|date=June 2017}} | {{Use Indian English|date=June 2017}} | ||
| Line 23: | Line 24: | ||
| relief =yes}} | | relief =yes}} | ||
| local-date = 20 October 1991 | | local-date = 20 October 1991 | ||
| local-time = 02:53 | | local-time = 02:53 [[Indian Standard Time]] ([[UTC+5:30]]) | ||
| duration = ~ 45 seconds<ref name=Kayal/> | | duration = ~ 45 seconds<ref name=Kayal/> | ||
| magnitude = 6.8 {{M|w|link=y}}<ref name="ISC-GEM"/> | | magnitude = 6.8 {{M|w|link=y}}<ref name="ISC-GEM"/> | ||
| Line 29: | Line 30: | ||
| location = {{coord|30.75|78.82|region:IN_type:event|display=inline,title}}<ref name="ISC-GEM"/> | | location = {{coord|30.75|78.82|region:IN_type:event|display=inline,title}}<ref name="ISC-GEM"/> | ||
| fault = | | fault = | ||
| type = [[ | | type = [[Fault (geology)#Dip-slip faults|Reverse]]<ref name="PAGER-CAT"/> | ||
| affected = [[India]] | | affected = [[Uttar Pradesh]] <br/> [[India]] | ||
| damage = [[United States dollar|$]]60 million<ref name=NGDC/> | | damage = [[United States dollar|$]]60 million<ref name=NGDC/> | ||
| intensity = | | intensity = {{MMI|9}}<ref name=Jain2/> | ||
| pga = .31''[[Peak ground acceleration|g]]''<ref name=Jain2/> | | pga = 0.31 ''[[Peak ground acceleration|g]]''<ref name=Jain2/> | ||
| tsunami = | | tsunami = | ||
| landslide = | | landslide = | ||
| Line 41: | Line 42: | ||
}} | }} | ||
The '''1991 Uttarkashi earthquake''' (also known as the '''Garhwal earthquake''') occurred at | The '''1991 Uttarkashi earthquake''' (also known as the '''Garhwal earthquake''') occurred at 02:53:16 [[Indian Standard Time]] ([[UTC+05:30]]) on 20 October with a moment magnitude of 6.8 and a maximum Mercalli intensity of IX (''Violent''). This thrust event was instrumentally recorded and occurred along the Main Central Thrust in the [[Uttarkashi]] and Gharwal regions of the [[India]]n state of [[Uttarakhand]] (then still part of [[Uttar Pradesh]]). High intensity shaking resulted in the deaths of at least 768 people and the destruction of thousands of homes. | ||
==Tectonic setting== | ==Tectonic setting== | ||
{{See also|Geology of the Himalaya}} | {{See also|Geology of the Himalaya}} | ||
The [[Garhwal division]] in northern India, flanked by the [[Tons River]] to the west and the [[Alaknanda River]] to the east, is located at the boundary of the [[Indian | The [[Garhwal division]] in northern India, flanked by the [[Tons River]] to the west and the [[Alaknanda River]] to the east, is located at the boundary of the [[Indian plate|Indian]] and [[Eurasian plate|Eurasian]] tectonic plates. In the region, the Indian plate is moving northeastward at a rate of {{convert|5|cm|sp=us}} per year. The Main Central Thrust is the primary northwest-striking structure and dips to the north at 30–40°. The fault plane solutions from the parametric catalogs for the 1991 and [[1999 Chamoli earthquake|1999]] events showed low-angle thrust faulting with varying amounts of strike-slip movement.<ref>{{citation|title=Himalayan hazard study on the basis of stress and strain state of 1991 Uttarkashi earthquake using Coulomb stress transfer model|first1=D. K.|last1=Gupta|first2=D.|last2=Bhowmick|first3=P. N. S.|last3=Roy|year=2015|journal=Geomatics, Natural Hazards, and Risk|volume=6|number=2|pages=133, 140|doi=10.1080/19475705.2013.820797|bibcode=2015GNHR....6..131G |doi-access=free}}</ref> | ||
==Earthquake== | ==Earthquake== | ||
| Line 55: | Line 56: | ||
===Damage=== | ===Damage=== | ||
Scientists from the [[Indian Institute of Technology Kanpur|Indian Institute of Technology Kanpur (IITK)]] conducted a survey of the affected areas between 27 October and 4 November. Their work revealed that more than 300,000 people in 1,294 villages were affected by the shock. Stone masonry homes (that usually supported heavy roofs) fared badly in areas where high intensity shaking occurred. The United States' [[National Geophysical Data Center]] indicates that 7,500 homes were damaged and another 7,500 were destroyed while the IITK report shows that up to 42,400 houses were damaged.<ref name=NGDC/><ref name=Jain>{{citation|title=Garhwal Earthquake of Oct. 20, 1991|url=http://www.nicee.org/eqe-iitk/uploads/EQR_Uttarkashi.pdf|first1=Sudhir. K.|last1=Jain|first2=Ramesh P.|last2=Singh|first3=Vinay K.|last3=Gupta|first4=Amit|last4=Nagar|year=1992|publisher=National Information Centre of Earthquake Engineering|series=EERI Special Earthquake Report|volume=26|number=2|pages=1–3}}</ref> | Scientists from the [[Indian Institute of Technology Kanpur|Indian Institute of Technology Kanpur (IITK)]] conducted a survey of the affected areas between 27 October and 4 November. Their work revealed that more than 300,000 people in 1,294 villages were affected by the shock. Stone masonry homes (that usually supported heavy roofs) fared badly in areas where high intensity shaking occurred. The United States' [[National Geophysical Data Center]] indicates that 7,500 homes were damaged and another 7,500 were destroyed while the IITK report shows that up to 42,400 houses were damaged.<ref name=NGDC/><ref name=Jain>{{citation|title=Garhwal Earthquake of Oct. 20, 1991|url=http://www.nicee.org/eqe-iitk/uploads/EQR_Uttarkashi.pdf|first1=Sudhir. K.|last1=Jain|first2=Ramesh P.|last2=Singh|first3=Vinay K.|last3=Gupta|first4=Amit|last4=Nagar|year=1992|publisher=National Information Centre of Earthquake Engineering|series=EERI Special Earthquake Report|volume=26|number=2|pages=1–3}}</ref> | ||
The United States' [[National Geophysical Data Center]] and the Belgian [[Centre for Research on the Epidemiology of Disasters]]' EM-DAT database both list 1,500 fatalities for the event with EM-DAT also listing 1,383 injuries. The USGS's Preliminary Determination of Epicenters and the Utsu catalog both list 2,000 deaths and 1,800 injured.<ref name="PAGER-CAT"/> | |||
===Intensity=== | ===Intensity=== | ||
{{see also|Earthquake zones of India}} | {{see also|Earthquake zones of India}} | ||
{{harvnb|Jain|Singh|Gupta|Nagar|1992}} stated that the shock was generally moderate while further clarifying the intensities that were observed at specific locations. Ghansyali, Gongotri, and [[Tehri]] were listed as experiencing intensity VII (''Very strong'') shaking and Bhatwari, Budhakedar, Krishanpur, Mahinanda, Maneri, and [[Uttarkashi]] were listed as experiencing intensity VIII (''Severe'') shaking. In a report that documented the study of strong motion recordings of the event, {{harvnb|Jain|Das|1993}} clarified that while Bhatwari and Uttarkashi experienced intensity VIII shaking at distances of {{convert|25|km|abbr=on}} and {{convert|40|km|abbr=on}} respectively, there was a small 20 km square mile area that experienced a maximum intensity of IX (''Violent'').<ref name=Jain2>{{citation|title=Analysis of Strong Motion Records from Uttarkashi Earthquake for Assessment of Code Provisions for Different Seismic Zones|url=http://www.iitk.ac.in/nicee/skj/Research_Papers/ANALYSIS%20OF%20STRONG%20MOTION%20RECORDS%20FROM%20UTTARKASHI_39.pdf|first1=Sudhir K.|last1=Jain|first2=Satrajit|last2=Das|date=1993|journal=Earthquake Spectra|volume=9|number=4|pages=739, 742|doi=10.1193/1.1585738|s2cid=128901914}}</ref><ref name=Jain/> | {{harvnb|Jain|Singh|Gupta|Nagar|1992}} stated that the shock was generally moderate while further clarifying the intensities that were observed at specific locations. Ghansyali, Gongotri, and [[Tehri]] were listed as experiencing intensity VII (''Very strong'') shaking and Bhatwari, Budhakedar, Krishanpur, Mahinanda, Maneri, and [[Uttarkashi]] were listed as experiencing intensity VIII (''Severe'') shaking. In a report that documented the study of strong motion recordings of the event, {{harvnb|Jain|Das|1993}} clarified that while Bhatwari and Uttarkashi experienced intensity VIII shaking at distances of {{convert|25|km|abbr=on}} and {{convert|40|km|abbr=on}} respectively, there was a small 20 km square mile area that experienced a maximum intensity of IX (''Violent'').<ref name=Jain2>{{citation|title=Analysis of Strong Motion Records from Uttarkashi Earthquake for Assessment of Code Provisions for Different Seismic Zones|url=http://www.iitk.ac.in/nicee/skj/Research_Papers/ANALYSIS%20OF%20STRONG%20MOTION%20RECORDS%20FROM%20UTTARKASHI_39.pdf|first1=Sudhir K.|last1=Jain|first2=Satrajit|last2=Das|date=1993|journal=Earthquake Spectra|volume=9|number=4|pages=739, 742|doi=10.1193/1.1585738|bibcode=1993EarSp...9..739J |s2cid=128901914}}</ref><ref name=Jain/> | ||
==See also== | ==See also== | ||
*[[List of earthquakes in 1991]] | |||
*[[List of earthquakes in India]] | *[[List of earthquakes in India]] | ||
*[[1999 Chamoli earthquake]] | |||
*[[Tehri Dam]] | *[[Tehri Dam]] | ||
==References== | ==References== | ||
<references> | |||
<ref name="ISC-GEM">{{citation|title=ISC-GEM Global Instrumental Earthquake Catalogue (1900–2012)|url=http://www.isc.ac.uk/iscgem/index.php|author=ISC|year=2016|publisher=[[International Seismological Centre]]|series=Version 3.0}}</ref> | <ref name="ISC-GEM">{{citation|title=ISC-GEM Global Instrumental Earthquake Catalogue (1900–2012)|url=http://www.isc.ac.uk/iscgem/index.php|author=ISC|year=2016|publisher=[[International Seismological Centre]]|series=Version 3.0}}</ref> | ||
<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> | <ref name=NGDC>{{citation|title=Significant Earthquake Database|url=https://www.ngdc.noaa.gov/nndc/struts/form?t=101650&s=1&d=1|archive-url=https://web.archive.org/web/20060929000601/http://www.ngdc.noaa.gov/nndc/struts/form?t=101650&s=1&d=1|url-status=dead|archive-date=29 September 2006|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> | ||
<ref name="PAGER-CAT">{{citation|title=PAGER-CAT Earthquake Catalog|url=https://earthquake.usgs.gov/static/lfs/data/pager/catalogs/ | <ref name="PAGER-CAT">{{citation|title=PAGER-CAT Earthquake Catalog|url=https://earthquake.usgs.gov/static/lfs/data/pager/catalogs/PAGER_CAT_v2.zip|date=4 September 2009|publisher=United States Geological Survey|series=Version 2008_06.1}}</ref> | ||
<ref name=Kayal>{{citation|title= Precursor seismicity, foreshocks and aftershocks of the Uttarkashi earthquake of October 20, 1991 at Garhwal Himalaya|first=J. R.|last=Kayal|year=2015|journal=Tectonophysics|volume=263|issue=1–3|page=339|doi=10.1016/S0040-1951(97)81488-6|bibcode=1996Tectp.263..339K}}</ref> | <ref name=Kayal>{{citation|title= Precursor seismicity, foreshocks and aftershocks of the Uttarkashi earthquake of October 20, 1991 at Garhwal Himalaya|first=J. R.|last=Kayal|year=2015|journal=Tectonophysics|volume=263|issue=1–3|page=339|doi=10.1016/S0040-1951(97)81488-6|bibcode=1996Tectp.263..339K}}</ref> | ||
</references> | |||
==Further reading== | |||
*{{citation|title=Seismotectonics of the 20 October 1991 Uttarkashi earthquake in Garhwal, Himalaya, North India|url=http://cat.inist.fr/?aModele=afficheN&cpsidt=4032621|first1=V. C.|last1=Thakur|first2=K.|last2=Sushil|year=1994|journal=Terra Nova|volume=6|number=1|pages=90–94|doi=10.1111/j.1365-3121.1994.tb00637.x|bibcode=1994TeNov...6...90T|url-access=subscription}} | |||
*{{citation|title=Seismotectonics of the 20 October 1991 Uttarkashi earthquake in Garhwal, Himalaya, North India|url=http://cat.inist.fr/?aModele=afficheN&cpsidt=4032621|first1=V. C.|last1=Thakur|first2=K.|last2=Sushil|year=1994|journal=Terra Nova|volume=6|number=1|pages=90–94|doi=10.1111/j.1365-3121.1994.tb00637.x|bibcode=1994TeNov...6...90T}} | *{{citation|title=The Uttarkashi earthquake of 20 October: Implications and lessons|last1=Valdiya|first1=K. S.|journal=Current Science|year=1991|volume=61|issue=12|pages=801–803|jstor=24095349}} | ||
{{ | |||
==External links== | ==External links== | ||
*[https://earthquake.usgs.gov/earthquakes/eventpage/usp0004y1r#executive M 6.8 | *[https://earthquake.usgs.gov/earthquakes/eventpage/usp0004y1r#executive M 6.8 – Uttaranchal, India] – [[United States Geological Survey]] | ||
*[https://web.archive.org/web/20161111122940/https://www.himalayanclub.org/hj/62/5/the-great-himalayan-earthquakes/ The Great Himalayan Earthquakes] – ''[[Himalayan Journal]]'' | *[https://web.archive.org/web/20161111122940/https://www.himalayanclub.org/hj/62/5/the-great-himalayan-earthquakes/ The Great Himalayan Earthquakes] – ''[[Himalayan Journal]]'' | ||
*{{EQ-isc-link|317038}} | *{{EQ-isc-link|317038}} | ||
| Line 87: | Line 91: | ||
{{Earthquakes in India}} | {{Earthquakes in India}} | ||
{{Himalayan earthquakes}} | {{Himalayan earthquakes}} | ||
[[Category:1991 disasters in India|Uttarkashi Earthquake, 1991]] | [[Category:1991 disasters in India|Uttarkashi Earthquake, 1991]] | ||
| Line 98: | Line 97: | ||
[[Category:Earthquakes in India]] | [[Category:Earthquakes in India]] | ||
[[Category:History of Uttarakhand (1947–present)]] | [[Category:History of Uttarakhand (1947–present)]] | ||
[[Category:October 1991 | [[Category:October 1991 in India]] | ||
[[Category:Uttarkashi district]] | [[Category:Uttarkashi district]] | ||
[[Category:1990s in Uttar Pradesh]] | |||
Latest revision as of 02:50, 16 March 2026
  Lahore Delhi Kathmandu  | |
| UTC time | 1991-10-19 21:23:14 |
|---|---|
| ISC event | 317038 |
| USGS-ANSS | ComCat |
| Local date | 20 October 1991 |
| Local time | 02:53 Indian Standard Time (UTC+5:30) |
| Duration | ~ 45 seconds[1] |
| Magnitude | 6.8 Mw[2] |
| Depth | 11.6 km (7 mi)[2] |
| Epicenter | 30°45′N 78°49′E / 30.75°N 78.82°E[2] |
| Type | Reverse[3] |
| Areas affected | Uttar Pradesh India |
| Total damage | $60 million[4] |
| Max. intensity | IX (Violent)[5] |
| Peak acceleration | 0.31 g[5] |
| Casualties | 768–2,000 dead[3] 1,383–1,800 injured[3] |
The 1991 Uttarkashi earthquake (also known as the Garhwal earthquake) occurred at 02:53:16 Indian Standard Time (UTC+05:30) on 20 October with a moment magnitude of 6.8 and a maximum Mercalli intensity of IX (Violent). This thrust event was instrumentally recorded and occurred along the Main Central Thrust in the Uttarkashi and Gharwal regions of the Indian state of Uttarakhand (then still part of Uttar Pradesh). High intensity shaking resulted in the deaths of at least 768 people and the destruction of thousands of homes.
Tectonic setting[edit | edit source]
The Garhwal division in northern India, flanked by the Tons River to the west and the Alaknanda River to the east, is located at the boundary of the Indian and Eurasian tectonic plates. In the region, the Indian plate is moving northeastward at a rate of 5 centimeters (2.0 in) per year. The Main Central Thrust is the primary northwest-striking structure and dips to the north at 30–40°. The fault plane solutions from the parametric catalogs for the 1991 and 1999 events showed low-angle thrust faulting with varying amounts of strike-slip movement.[6]
Earthquake[edit | edit source]
Six three-axis accelerometers that were within 60 km (37 mi) captured the event, including two units that were close to the projection of the fault at the surface. Analysis of the data recorded by these devices revealed the distribution of slip, moment release over time, and the location of the maximum slip. The mechanism of the event was typical of the thrust system of the Himalayas, with maximum slip (1.5 m (4 ft 11 in)) occurring to the west and southwest of the hypocenter. Energy release began slowly and built to a crescendo four seconds after the initiation of the rupture.[7]
Damage[edit | edit source]
Scientists from the Indian Institute of Technology Kanpur (IITK) conducted a survey of the affected areas between 27 October and 4 November. Their work revealed that more than 300,000 people in 1,294 villages were affected by the shock. Stone masonry homes (that usually supported heavy roofs) fared badly in areas where high intensity shaking occurred. The United States' National Geophysical Data Center indicates that 7,500 homes were damaged and another 7,500 were destroyed while the IITK report shows that up to 42,400 houses were damaged.[4][8]
The United States' National Geophysical Data Center and the Belgian Centre for Research on the Epidemiology of Disasters' EM-DAT database both list 1,500 fatalities for the event with EM-DAT also listing 1,383 injuries. The USGS's Preliminary Determination of Epicenters and the Utsu catalog both list 2,000 deaths and 1,800 injured.[3]
Intensity[edit | edit source]
Jain et al. 1992 stated that the shock was generally moderate while further clarifying the intensities that were observed at specific locations. Ghansyali, Gongotri, and Tehri were listed as experiencing intensity VII (Very strong) shaking and Bhatwari, Budhakedar, Krishanpur, Mahinanda, Maneri, and Uttarkashi were listed as experiencing intensity VIII (Severe) shaking. In a report that documented the study of strong motion recordings of the event, Jain & Das 1993 clarified that while Bhatwari and Uttarkashi experienced intensity VIII shaking at distances of 25 km (16 mi) and 40 km (25 mi) respectively, there was a small 20 km square mile area that experienced a maximum intensity of IX (Violent).[5][8]
See also[edit | edit source]
References[edit | edit source]
- ↑ Kayal, J. R. (2015), "Precursor seismicity, foreshocks and aftershocks of the Uttarkashi earthquake of October 20, 1991 at Garhwal Himalaya", Tectonophysics, 263 (1–3): 339, Bibcode:1996Tectp.263..339K, doi:10.1016/S0040-1951(97)81488-6
- ↑ 2.0 2.1 2.2 ISC (2016), ISC-GEM Global Instrumental Earthquake Catalogue (1900–2012), Version 3.0, International Seismological Centre
- ↑ 3.0 3.1 3.2 3.3 PAGER-CAT Earthquake Catalog, Version 2008_06.1, United States Geological Survey, 4 September 2009
- ↑ 4.0 4.1 National Geophysical Data Center / World Data Service (NGDC/WDS) (1972), Significant Earthquake Database (Data Set), National Geophysical Data Center, NOAA, doi:10.7289/V5TD9V7K, archived from the original on 29 September 2006
- ↑ 5.0 5.1 5.2 Jain, Sudhir K.; Das, Satrajit (1993), "Analysis of Strong Motion Records from Uttarkashi Earthquake for Assessment of Code Provisions for Different Seismic Zones" (PDF), Earthquake Spectra, 9 (4): 739, 742, Bibcode:1993EarSp...9..739J, doi:10.1193/1.1585738, S2CID 128901914
- ↑ Gupta, D. K.; Bhowmick, D.; Roy, P. N. S. (2015), "Himalayan hazard study on the basis of stress and strain state of 1991 Uttarkashi earthquake using Coulomb stress transfer model", Geomatics, Natural Hazards, and Risk, 6 (2): 133, 140, Bibcode:2015GNHR....6..131G, doi:10.1080/19475705.2013.820797
- ↑ Cotton, F.; Campillo, M.; Deschamps, A.; Rastogi, B. K. (1991), "Rupture history and seismotectonics of the 1991 Uttarkashi, Himalaya earthquake", Tectonophysics, 258 (1–4): 35–51, Bibcode:1996Tectp.258...35C, doi:10.1016/0040-1951(95)00154-9
- ↑ 8.0 8.1 Jain, Sudhir. K.; Singh, Ramesh P.; Gupta, Vinay K.; Nagar, Amit (1992), Garhwal Earthquake of Oct. 20, 1991 (PDF), EERI Special Earthquake Report, vol. 26, National Information Centre of Earthquake Engineering, pp. 1–3
Further reading[edit | edit source]
- Thakur, V. C.; Sushil, K. (1994), "Seismotectonics of the 20 October 1991 Uttarkashi earthquake in Garhwal, Himalaya, North India", Terra Nova, 6 (1): 90–94, Bibcode:1994TeNov...6...90T, doi:10.1111/j.1365-3121.1994.tb00637.x
- Valdiya, K. S. (1991), "The Uttarkashi earthquake of 20 October: Implications and lessons", Current Science, 61 (12): 801–803, JSTOR 24095349
External links[edit | edit source]
- M 6.8 – Uttaranchal, India – United States Geological Survey
- The Great Himalayan Earthquakes – Himalayan Journal
- The International Seismological Centre has a bibliography and/or authoritative data for this event.