2011 Burma earthquake

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2011 Burma earthquake
2011 Burma earthquake is located in Burma
2011 Burma earthquake
Date 20:25:23, 24 March 2011 (UTC+06:30) (2011-03-24T20:25:23UTC+06:30)
Duration 1 minute
Magnitude 6.9 Mw
Depth 10 km (6.21 mi)
Epicenter 20°42′18″N 99°56′56″E / 20.705°N 99.949°E / 20.705; 99.949Coordinates: 20°42′18″N 99°56′56″E / 20.705°N 99.949°E / 20.705; 99.949
Countries or regions Burma, Thailand, Laos, China, Vietnam
Max. intensity Mercalli IX
Casualties 151 killed, 212 injured [1]

The 2011 Burma earthquake (Burmese: ၂၀၁၁ မြန်မာငလျင်) was a magnitude 6.9 earthquake on 24 March 2011 that had its epicenter in the east of Shan State in Burma (Myanmar) with a hypocenter 10 km deep.[2] It had two aftershocks, one of magnitude 4.8, another at magnitude 5.4[3] and two subsequent shock at magnitude 5.0 and 6.2. The quake's epicentre was 70 miles (110 km) from the northern Thai city of Chiang Rai, north of Mae Sai and southeast of Kentung.[4]

Geology[edit]

USGS ShakeMap of the earthquake, showing shaking intensity.

The earthquake occurred in an area of complex tectonics caused by the continuing collision between the northward moving Indo-Australian Plate and the Eurasian Plate, which created the Arakan Yoma mountains. In this zone of highly oblique collision, most of the motion is accommodated by the north-south trending Sagaing fault, a major dextral (right lateral) strike-slip fault that runs through the western and central part of Burma. The remaining component of shortening across this zone causes distributed deformation of eastern Burma and Thailand extending into Laos. This deformation is partly accommodated by a set of southwest-northeast trending sinistral (left lateral) strike-slip faults.[5] The faults closest to the epicenter of the earthquake are the Mae Chan and Nam Ma faults.[6] The focal mechanism for this earthquake is consistent with left-lateral movement on one of these faults,[2] away from the main zones of seismic activity in Burma.[7] Other recent significant earthquakes in this area included the 2011 Yunnan earthquake and the 2007 Laos earthquake.[8] According to the Earth Observatory of Singapore, it appears likely that the earthquake was caused by motion on the western segment of the Nan Ma Fault.[9]

Casualties[edit]

A road damaged by the earthquake in Tarlay, Shan State
The earthquake destroyed dozens of houses in Shan State

Early reports suggested that at least 10 people were killed by quake-triggered landslides in the town of Tachileik, including a child, as well as Tarpin to its north, both in Shan State, northeastern Burma.[10] Another person was killed in Mae Sai, Thailand, near the Burmese border.[11] At least three injuries were reported in Burma.

After sunrise, the casualty toll increased to 24 in Burma, in addition to the one fatality in Thailand. Officials warned that the death toll is likely to rise.[12] Later, death toll rose to 74 killed in Burma and 1 in Thailand,[13][14] while 111 people were injured. In Tarlay, located between Tachileik and Mong Hpyak, at least 40 were killed when 130 houses collapsed. Vertical displacement of 1.5 metres in subsidence was observed in the area.[15]

The Bangkok Post reported on 27 March 2011 that the death toll was "over 150", which is double the official figure of 75.[16][17]

Aftermath[edit]

Temporary evacuations of tall buildings took place in Chiang Rai, Menghai County in Yunnan, Nanning in Guangxi Zhuang Autonomous Region, and in Hanoi of Vietnam.[18][19] At least one bridge is reported collapsed in Myanmar.[20] In total, 390 residential homes, 14 monasteries and 9 government buildings were destroyed. In Monglin, at least 128 homes were reduced to rubble.[21] According to the United States Geological Survey's population exposure data, the final damages from the earthquake are most likely to be slightly under USD $100 million.[22]

References[edit]

  1. ^ "CATDAT Damaging Earthquakes Database 2011 – Annual Review". Earthquake Report. 9 January 2012. Retrieved 14 January 2012. 
  2. ^ a b Magnitude 6.8 – MYANMAR
  3. ^ Earthquakes, USGS. "Magnitude 5.4 – MYANMAR". United States Geological Survey. Earthquake Hazards Program. Archived from the original on 31 March 2011. Retrieved 24 March 2011. 
  4. ^ "North-east Burma hit by two 7.0 magnitude earthquakes". BBC. 24 March 2011. Archived from the original on 24 March 2011. Retrieved 24 March 2011. 
  5. ^ USGS (12 May 2012). "Magnitude 6.9 - MYANMAR:Earthquake Summary". United States Geological Survey. Retrieved 11 November 2012. 
  6. ^ Morley, C.K. (2007). "Variations in Late Cenozoic–Recent strike-slip and oblique-extensional geometries, within Indochina: The influence of pre-existing fabrics". Journal of Structural Geology 29 (1). Bibcode:2007JSG....29...36M. doi:10.1016/j.jsg.2006.07.003. Retrieved 25 March 2011. 
  7. ^ Hazard Risk Profile, ASEAN. "Earthquake". Post Nargis Knowledge Management Portal. Disaster Risk Management. Retrieved 24 March 2011. 
  8. ^ USGS, 16 May 2007. "M6.3 – Laos". United States Geological Survey. Did You Feel It?. Retrieved 25 March 2011. 
  9. ^ http://www.earthobservatory.sg/media/news-and-features/295-myanmar-earthquake-of-march-24th-magnitude-68.html
  10. ^ Yan, Xinhuanet (25 March 2011). "At least 10 killed in 7.0-magnitude quake in Myanmar". Xinhua. Archived from the original on 1 May 2011. Retrieved 24 March 2011. 
  11. ^ News, BNO (24 March 2011). "Powerful earthquake rocks Myanmar, deaths reported". Channel 6 News Thailand. Retrieved 24 March 2011. 
  12. ^ Reuters, TVNZ (25 March 2011). "Myanmar quake toll rises to 25". TVNZ. Retrieved 25 March 2011. 
  13. ^ Reuters, JPost (25 March 2011). "Quake kills 74 in Myanmar, aftershock rattles Thailand". The Jerusalem Post. Retrieved 25 March 2011. 
  14. ^ Asia, World (25 March 2011). "At least 75 killed in Burma quake: officials". Bangkok Post. Retrieved 25 March 2011. 
  15. ^ Zhang, Xiang (25 March 2011). "40 killed in Tarlay in Myanmar quake". Xinhua. Retrieved 25 March 2011. 
  16. ^ Bangprapa, Mongkol; Kultida Ssmabuddhi (27 March 2011). "Burmese quake toll 'over 150' – Journalist Tells of Chaotic Relief Scene". The Bangkok Post. Retrieved 3 April 2011. 
  17. ^ http://www.bangkokpost.com/news/local/228786/burmese-quake-toll-over-150
  18. ^ AFP, South Asia (25 March 2011). "Two dead as strong quake hits Myanmar: Officials". The Straits Times. Retrieved 24 March 2011. 
  19. ^ Yan, Xinhuanet (25 March 2011). "Myanmar quake rocks part of south China". Xinhua. Retrieved 24 March 2011. 
  20. ^ Htay, Hla Hla (25 March 2011). y.com.au/breaking-news-world/two-dead-as-strong-quake-hits-burma-20110325-1c8ra.html "Two dead as strong quake hits Burma". WA today. Retrieved 24 March 2011. 
  21. ^ Fang, Yang (25 March 2011). "Death toll of Myanmar's earthquake rises to 74, 111 people injured". Xinhua. Retrieved 25 March 2011. 
  22. ^ Earthquakes, USGS. "PAGER – M 6.8 – MYANMAR". United States Geological Survey. PAGER. Retrieved 25 March 2011. 

External links[edit]