View source for 2021 Assam earthquake

{{Short description|Earthquake in India}}
{{Infobox earthquake
| isc-event = 620343980
| magnitude = 6.0 {{M|w|link=y}}<ref name="USGS">{{cite web |title=M 6.0 - 9 km NNW of Dhekiajuli, India |url=https://earthquake.usgs.gov/earthquakes/eventpage/us7000dy3b/executive |website=earthquake.usgs.gov |publisher=USGS |access-date=14 May 2021}}</ref>
| local-time = 07:51 [[Time in India|(IST)]]
| location = {{Coord|26.781|N|92.457|E}}
| anss-url = https://earthquake.usgs.gov/earthquakes/eventpage/us7000dy3b/
| name = 2021 Assam earthquake
| timestamp = 2021-04-28 02:21:26 
| map2 ={{Location map|India Assam#India
|lat=26.77
|long=92.43
|mark=Bullseye1.png
|marksize=50
|position=top
|width=260
|caption=
|relief=yes
|label=}}
| alt = 
| depth = 34.0 km (21.1 mi)
| intensity = {{MMI|VII}}
| image = 
| local-date = 28 April 2021
| aftershocks = Several. The strongest so far is a {{M|w}} 4.7<ref>{{cite web |title=Explained: In Assam earthquake, reminder of seismic hazard along HFT faultline|url=https://indianexpress.com/article/explained/explained-in-assam-earthquake-reminder-of-seismic-hazard-along-hft-faultline-7292770/ |publisher=The Indian Express  |access-date=28 April 2021}}</ref>
| fault = Kopili Fault
| casualties = 2 dead, 12 injured
| countries affected = [[Bangladesh]], [[China]], [[Myanmar]], [[Bhutan]], and [[India]]
}}

The '''2021 Assam earthquake''' struck 11 km (7 miles) away from [[Assam|Dhekiajuli, Assam, India]] at 07:51 [[Time in India|(IST)]] on April 28, 2021 with a richter scale magnitude of 6.4.<ref>{{Cite web|date=2021-04-28|title=Northeast India hit by magnitude 6.4 earthquake|url=https://www.independent.co.uk/asia/india/india-earthquake-today-assam-latest-b1838656.html |archive-url=https://web.archive.org/web/20210428175455/https://www.independent.co.uk/asia/india/india-earthquake-today-assam-latest-b1838656.html |archive-date=2021-04-28 |url-access=limited |url-status=live|access-date=2021-04-28|website=The Independent|language=en}}</ref> The quake struck at a depth of 34 km (21 miles), 140 km (86 miles) north of the main city of [[Guwahati]]. It resulted in two fatalities and at least 12 injuries.

==Tectonic setting==
The tectonics of the Assam region is dominated by convergence of the India, Burma and Eurasian plates. Major fault structures like the [[Main Frontal Thrust]], Main Boundary Thrust and [[Main Central Thrust]], all splay branches of the [[Main Himalayan Thrust]], accommodate the shortening rate as India is pushing into Asia. The large 8.6 {{M|w}} [[1950 Assam–Tibet earthquake|Assam–Tibet earthquake]] in 1950 was a megathrust earthquake that resulted from a rupture along the Main Himalayan Thrust and Main Frontal Thrust.

== Earthquake ==
[[File:2021-04-28 Dhekiajuli, India M6 earthquake shakemap (USGS).jpg|right|thumb|Earthquake Intensity Map]]
The earthquake occurred as a result of oblique-slip faulting at a shallow depth just at the foothills of the Himalayas.<ref>{{cite web |title=Assam Earthquake: 6.4 magnitude quake, 7 aftershocks jolt Northeast, tremors felt in Bengal |url=https://www.indiatoday.in/india/story/earthquake-in-northeast-tremors-felt-in-assam-north-bengal-arunachal-pradesh-1795696-2021-04-28 |publisher=[[India Today]] |access-date=28 April 2021}}</ref><ref>{{Cite web|title=Official Website of National Center of Seismology|url=https://seismo.gov.in/MIS/riseq/interactive/index/ZVNoMWsrTTlhMEZUUXN1UEgxbUcxUT09/Reviewed|access-date=2021-05-03|website=seismo.gov.in}}</ref> Analysis by India's [[National Centre for Seismology]] revealed that the earthquake involved slip along the Kopili Fault, near the [[Main Frontal Thrust]].<ref name="BB">{{cite news |last1=Chakravartty |first1=Anupam |title=Assam earthquake: Known to cause deadly tremors, Kopili fault eludes experts |url=https://www.eastmojo.com/assam/2021/04/29/assam-earthquake-known-to-cause-deadly-tremors-kopili-fault-eludes-experts/ |access-date=15 May 2021 |agency=EastMojo |date=29 April 2021}}</ref> This is a northeast striking fault structure that runs from east of the Shillong Plateau, through the Assam Valley and into Bhutan for a total estimated length of 300 km, and a width of 30 km.<ref name="AA">{{cite journal |last1=Kayal, J., Arefiev, S., Baruah, S., Tatevossian, R., Gogoi, N., Sanoujam, M., Gautam, J.L., Hazarika, D., & Borah, D. |title=The 2009 Bhutan and Assam felt earthquakes (Mw 6.3 and 5.1) at the Kopili fault in the northeast Himalaya region |journal=Geomatics, Natural Hazards and Risk |date=2010 |volume=1 |issue=3 |pages=273-281 |doi=10.1080/19475705.2010.486561|doi-access=free }}</ref> Its predominant slip sense is right-lateral strike-slip.<ref>{{cite web |last1=Kharita |first1=Akash |title=Strong earthquake jolts Assam |url=https://temblor.net/earthquake-insights/strong-earthquake-jolts-assam-12692/ |website=Temblor |access-date=15 May 2021 |doi=10.32858/temblor.171}}</ref>

The same fault is believed to have caused the an {{M|wb}} 6.1 [[2009 Bhutan earthquake|earthquake in Bhutan]] in 2009, killing 11 and injuring dozens.<ref>{{cite web |title=M 6.1 - Bhutan |url=https://earthquake.usgs.gov/earthquakes/eventpage/usp000h1r4/executive |website=earthquake.usgs.gov |publisher=USGS |access-date=15 May 2021}}</ref> Two other {{M|w}} 7.0+ earthquakes rocked the Assam Valley in [[1869 Cachar earthquake|1869]] and 1943, is believed to have been on this fault, as well as the deadly [[2016 Imphal earthquake]].<ref name="AA" />

== Impact ==
The earthquake caused moderate but widespread damage to nearby buildings, but no collapses were reported.<ref>{{Cite web|date=2021-04-28|title=Quake of magnitude 6 strikes India's Assam, damages some buildings|url=https://www.reuters.com/world/india/magnitude-62-earthquake-strikes-assam-india-emsc-2021-04-28/|access-date=2021-04-28|website=Reuters}}</ref> Among the buildings affected was a multi-story structure in Nagaon which tilted to its side and leaned against an adjacent building. Cracks also appeared in the walls of homes and commercial buildings. A few vehicles were damaged when bricks fell on them.<ref>{{cite news |title=From damage caused to relief operations, Assam earthquake explained in 10 points |url=https://www.indiatoday.in/coronavirus-outbreak/story/damage-caused-relief-operations-assam-earthquake-1796077-2021-04-29 |access-date=15 May 2021 |agency=India Today |date=29 April 2021 |location=New Delhi}}</ref> Landslides and liquefaction of the ground were reported in Assam.<ref>{{cite news |title=Cracked roads, tilted buildings: Assam earthquake captured in scary photos, videos |url=https://www.indiatoday.in/india/story/massive-earthquake-assam-buildings-damaged-walls-cracked-photos-videos-1795765-2021-04-28 |access-date=15 May 2021 |agency=India Today |date=28 April 2021 |location=New Delhi}}</ref> Damage to buildings were also reported in nearby Bhutan, and two individuals were injured.<ref>{{cite news |title=Earthquake causes structural damage |url=https://kuenselonline.com/earthquake-causes-structural-damage/ |access-date=15 May 2021 |agency=kuenselonline.com}}</ref> Two people in the Kamrup Metro and Nagaon districts died of heart attacks caused by the earthquake while 12 others suffered injuries.<ref>{{cite news |last1=Saha |first1=Abhishek |title=Assam earthquake: At least 10 injured, houses damaged |url=https://indianexpress.com/article/north-east-india/assam/assam-bengal-earthquake-7291892/ |access-date=15 May 2021 |agency=The Indian Express |date=29 April 2021 |location=Guwahati}}</ref><ref>{{cite news |title=Two die of shock after 6.4 magnitude quake in Assam |url=https://www.thehindu.com/news/national/other-states/earthquake-of-magnitude-64-strikes-assam/article34427787.ece |access-date=15 May 2021 |agency=The Hindu |date=28 April 2021}}</ref>

==See also==

*[[List of earthquakes in 2021]]
*[[List of earthquakes in India]]

== References ==
{{reflist}}

{{Earthquakes in 2021}}
{{Earthquakes in India}}
{{Himalayan earthquakes}}

{{#seo:
|keywords=2021 earthquakes, Earthquakes in India, Earthquakes in Assam, Earthquakes in Bhutan, 2021 disasters in India, 2021 earthquakes in Asia
|description=
}}

[[Category:2021 earthquakes]]
[[Category:Earthquakes in India]]
[[Category:Earthquakes in Assam]]
[[Category:Earthquakes in Bhutan]]
[[Category:2021 disasters in India]]
[[Category:2021 earthquakes in Asia]]