2008 Sichuan earthquake

2008 Sichuan earthquake ; Wenchuan earthquake ; 汶川大地震
Coordinates	31 ° 1 ′ 16 ″ N , 103 ° 22 ′ 1 ″ E Coordinates: 31 ° 1 ′ 16 ″ N , 103 ° 22 ′ 1 ″ E
date	May 12, 2008
Time	06:28:01 ( Local time ) ; (22:28:01 UTC )
Magnitude	7.9 M W
depth	19 km
epicenter	District Wenchuan , Sichuan
country	People's Republic of China
dead	69,227
Injured	374,643
Missing	17,923
	; USGS map of the earthquake

The earthquake in Sichuan ( Chinese 汶川大地震 , Pinyin Wènchuān dà dìzhèn - "Great Earthquake of Wenchuan") was a severe earthquake that occurred on May 12, 2008 at 06:28:01 UTC (14:28:01 local time) occurred in the Chinese province of Sichuan and adjacent areas. It claimed nearly 70,000 victims and damaged more than five million buildings. 5.8 million people were left homeless.

Tectonic situation in the region

The earthquake occurred as a result of movement in the Longmenshan fault zone on the northwestern edge of the Sichuan Basin. Both the geographical location of the epicenter and the focus mechanism are in good agreement with a stress break along this fault zone. The evaluations indicate movement on the Beichuan Fault, a southeastern element of the Longmenshan fault zone.

The seismic activity in Central and East Asia is due to the convergent plate motion . The earthquake reflected the tectonic tension situation resulting from the movement of the Indian plate against the Eurasian plate . The Indian plate moves about 50 mm northwards every year. This movement is absorbed by the uplift of the Tibetan highlands and the movement of parts of the earth's crust in this zone in an easterly direction. In the process, crust material from the high-lying western Tibetan plateau is slowly pressed against the solid crust below the Sichuan basin and southeastern China. This pressure created thrust zones such as the Longmenshan Zone, where the material shifting to the east is pushed over the western edge of the Sichuan Basin.

The affected area has been hit by destructive earthquakes before. An earthquake on September 12, 1850 with a magnitude of 7.5 claimed 20,000 victims, and a quake on August 25, 1933 with a magnitude of 7.5 killed more than 9,300 people.

A connection with the filling of the Zipingpu dam , under which the hypocenter of the earthquake was located, was discussed in specialist circles .

Earthquakes since 1900 in the region with a magnitude ≥ 7.0
date	Time	Coordinates	Depth (km)	Magnitude
1917-07-30	23:54	28 ° 0 ′ 0 ″ N , 104 ° 0 ′ 0 ″ E28 104	-	7.3
1923-03-24	12:40	30 ° 33 '10.8 " N , 101 ° 15' 28.8" E30,553 101,258	25th	7.2
1933-08-25	07:50	31 ° 48 ′ 36 " N , 103 ° 32 ′ 27.6" E31.81 103.541	25th	7.3
1947-03-17	08:19	33 ° 0 ′ 0 ″ N , 99 ° 30 ′ 0 ″ E33 99.5	-	7.5
1948-05-25	07:11	29 ° 30 ′ 0 ″ N , 100 ° 30 ′ 0 ″ E29.5 100.5	-	7.2
1950-08-15	14:09	28 ° 30 ′ 0 ″ N , 96 ° 30 ′ 0 ″ E28.5 96.5	-	8.6
1955-04-14	01:29	29 ° 58 ′ 51.6 " N , 101 ° 36 ′ 46.8" E29,981 101,613	10	7.5
1967-08-30	04:22	31 ° 37 '51.6 " N , 100 ° 13' 55.2" E31,631 100,232	8.1	7.0
1973-02-06	10:37	31 ° 21 '39.6 " N , 100 ° 30' 14.4" E31,361 100,504	6.6	7.4
2008-05-12	06:28	31 ° 0 ′ 54 " N , 103 ° 21 ′ 54" E31,015 103,365	19th	7.9
Source: United States Geological Survey

The quake

The quake occurred on May 12, 2008 at 06:28:01 UTC (14:28:01 local time). Its average center ( geographical coordinates : 31 ° 1 ' N , 103 ° 22' O ) was located just outside the Sichuan basin in the large municipality Yingxiu ( 映秀镇 ) in circle Wenchuan of autonomous prefecture Ngawa , about 75 kilometers north-west of the metropolis Chengdu . The center of the quake was about nineteen kilometers deep, so it was a shallow quake, which tends to cause great damage. According to the United States Geological Survey, the quake reached a magnitude of 7.9 M _w . 31,015 103,365

The provinces of Sichuan, Gansu and Shanxi , as well as the direct government city of Chongqing were affected . The area involved covered more than 440,000 km² with a population of 45.61 million people. The effects of the earthquake could even be felt in Beijing , 1,550 kilometers away , in Shanghai , Hanoi and Bangkok .

After the main quake, there were a number of aftershocks, many of which were greater than 4.5 in magnitude .

Victim

region		Dead (estimate)
Sichuan	Mianyang	21,963
	Ngawa	20,258
	Deyang	17.121
	Guangyuan	4,822
	Cheng you	4,276
	Nanchong	30th
	Ya'an	28
	Suining	27
	Ziyang	20th
	Meishan	10
	Bazhong	10
	Garzê	9
	Leshan	8th
	Neijiang	7th
	Dazhou	4th
	Liangshan	3
	Zigong	2
	Luzhou	1
	Guang'an	1
	total	68,636
Gansu		365
Shaanxi		122
Chongqing		18th
Henan		2
Guizhou		1
Hubei		1
Hunan		1
Yunnan		1
Total number (estimate):		≥ 69,197

Most of the fatalities were reported in the areas of Mianyang , Deyang , Chengdu and Guangyuan cities . According to official information (as of September 25, 2008) the earthquake killed 69,227 people. 17,923 more were still missing at the time. 374,643 people were injured. 5.8 million people were left homeless.

Damage

As a result of the earthquake, entire villages and city districts collapsed, entire streets, factories and schools collapsed. More than five million buildings were damaged.

The stability of several dams on the Min River in particular was at risk. Cracks were found at Kuzhu Dam and the water levels at Zipingpu Dam were lowered to reduce pressure. The Three Gorges Dam has been, according to official press releases not damaged by the tremors. Since there are a large number of dams in the affected area, the authorities ordered an inspection of the structures.

A railway tunnel on the railway line from Baoji to Chengdu partially collapsed. A straight through freight train with 27 freight cars and 12 tank cars derailed. A fire broke out and the train burned out.

Further effects

The earthquake triggered many landslides and rockfalls, blocking road links in the affected region. This made the evacuation of the injured and the access of the rescue teams and aid supplies more difficult.

In several places, these landslides caused rivers to backflow because the respective river bed was blocked by the earth. The rising water created new threats, such as the rise in the water level above the height of the blockade or the growing pressure on the blockade. Such danger spots arose at Jian Jiang above Beichuan , for example , where the earthquake survivors and the rescue teams sought out areas higher up. The bursting of such a blockade led to the drowning of over two thousand people in the last earthquake in Sichuan with serious consequences in 1933. According to estimates by the authorities, the risk of such flooding affected 750,000 inhabitants of the region at times. Units of the Chinese army therefore prepared to blow up such barriers in order to allow the dammed water to drain away.

Since many of the victims were buried in the rubble and the recovery of the bodies was slow, the risk of epidemics increasing sharply.

aid

Chinese multimillionaire Chen Guangbiao spent 54 days in the earthquake zone, helping on site and donating over 100 million yuan (US $ 15 million).

reception

The Chinese artist Ai Weiwei researched thousands of schoolchildren who died in collapsed schools and came into conflict with the Chinese authorities. He created the large-format installation Straight on the subject .

literature

The Wenchuan Earthquake (May 12, 2008), Sichuan Province, China, and resulting geohazards , in: Natural Hazards, Volume 56, January 2011, pp. 19-36

Web links

Commons : Earthquake in Sichuan 2008 - Collection of pictures, videos and audio files

Ministry of Commerce of the People's Republic of China: Impact of the Earthquake on China's Economy , June 5, 2008
Satellite images from the region , www.universetoday.com

Individual evidence

↑ Rodolphe Cattin, Julia de Sigoyer, Manu Pubellier: Le séisme du Sichuan du May 12, 2008 Magnitude 7.9 ( French ) CNRS , Laboratoire de Géologie de l'Ecole normal supérieure. Retrieved May 21, 2008.

↑ H. Yao: Modeling crustal channel flow, crustal deformation and anisotropy with application to the Tibetan Plateau ( English ) Archived from the original on May 17, 2008. Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved May 14, 2008. @1@ 2

↑ Xichang - lishishang de dizhenqu ( Memento of the original from June 10, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (Xichang - historical earthquake area)

↑ Magnitude 7.9 - EASTERN SICHUAN, CHINA: Earthquake summary ( English ) United States Geological Survey . Retrieved May 12, 2008.

↑ Jane Qiu: Evidence Mounts for Dam-Quake Link. In: Science , Volume 336, No. 6079, 2012, p. 291, doi: 10.1126 / science.336.6079.291

↑ Magnitude 7.9 - EASTERN SICHUAN, CHINA. United States Geological Survey , accessed May 12, 2008 .

↑ Wang Zifa: A preliminary report on the Great Wenchuan Earthquake . In: Earthq Eng & Eng Vib . tape 7 , no. 2 , June 2008, p. 225-234 , doi : 10.1007 / s11803-008-0856-1 (English).

↑ GFZ Potsdam - Earthquake Bulletin

↑ 12 时汶川地震造成 34073 人遇难 245108 人受伤 (中国网) 更新 ( Chinese ) news.sina.com. Retrieved July 13, 2008.

↑ Death toll from China's May earthquake remains unchanged at 69,227 ( English ) Xinhua . Archived from the original on August 15, 2009. Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved September 25, 2008. @1@ 2