2013 April 20, Ya'an China Earthquake ShakeMap

The Lushan earthquake or Ya'an earthquake (, ''Yak-ngai Sayom'') occurred at 08:02

Beijing Time The time in China follows a single standard time offset of UTC+08:00 (eight hours ahead of Coordinated Universal Time), even though the country spans almost five geographical time zones. The official national standard time is called ''Beijing Ti ...

(00:02 UTC) on April 20, 2013. The epicenter was located in Lushan County,

Ya'an Ya'an (, Tibetan: Yak-Nga ) is a prefecture-level city in the western part of Sichuan province, China, located just below the Tibetan Plateau. The city is home to Sichuan Agricultural University, the only 211 Project university and the largest ...

Sichuan Sichuan (; zh, c=, labels=no, ; zh, p=Sìchuān; alternatively romanized as Szechuan or Szechwan; formerly also referred to as "West China" or "Western China" by Protestant missions) is a province in Southwest China occupying most of t ...

, about from

Chengdu Chengdu (, ; simplified Chinese: 成都; pinyin: ''Chéngdū''; Sichuanese pronunciation: , Standard Chinese pronunciation: ), alternatively romanized as Chengtu, is a sub-provincial city which serves as the capital of the Chinese provin ...

along the

Longmenshan Fault The Longmenshan Fault () is a thrust fault which runs along the base of the Longmen Mountains in Sichuan province in southwestern China. The strike of the fault plane is approximately NE. Motion on this fault is responsible for the uplift of th ...

in the same province heavily impacted by the 2008 Sichuan earthquake. The magnitude of the earthquake was placed at M_s 7.0 by China Earthquake Data Center, M_s 7.0 by

Russian Academy of Sciences The Russian Academy of Sciences (RAS; russian: Росси́йская акаде́мия нау́к (РАН) ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across t ...

, M_w 7.0 by

Geoscience Australia Geoscience Australia is an agency of the Australian Government. It carries out geoscientific research. The agency is the government's technical adviser on all aspects of geoscience, and custodian of the geographic and geological data and knowle ...

, M_w 6.6 by the

United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

(USGS), M_w 6.6 by the

European Alert System The European Alert System (sometimes referred to as the European Alarm System or European Warning System) is an earthquake warning system for member states of the Council of Europe's EUR-OPA Major Hazards Agreement. Seismic alerts are provided by ...

(EMSC) and M_j 6.9 by the

Japan Meteorological Agency The , abbreviated JMA, is an agency of the Ministry of Land, Infrastructure, Transport and Tourism. It is charged with gathering and providing results for the public in Japan that are obtained from data based on daily scientific observation an ...

(JMA). 1,815

aftershock In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousa ...

s have been recorded as of 00:00 (UTC+8h) April 22.

Tectonic setting

The active

plate tectonic Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large te ...

s of the

Sichuan Basin The Sichuan Basin (), formerly transliterated as the Szechwan Basin, sometimes called the Red Basin, is a lowland region in southwestern China. It is surrounded by mountains on all sides and is drained by the upper Yangtze River and its tributar ...

is dominated by the north–south

continental collision In geology, continental collision is a phenomenon of plate tectonics that occurs at convergent boundaries. Continental collision is a variation on the fundamental process of subduction, whereby the subduction zone is destroyed, mountains produ ...

of the

Indian Plate The Indian Plate (or India Plate) is a minor tectonic plate straddling the equator in the Eastern Hemisphere. Originally a part of the ancient continent of Gondwana, the Indian Plate broke away from the other fragments of Gondwana , began ...

and

Eurasian Plate The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent an ...

. As the Indian Plate collides along a

convergent plate boundary A convergent boundary (also known as a destructive boundary) is an area on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other, a process known as subduction. The subduction zone can be defined by a ...

known as the

Main Himalayan Thrust The Main Himalayan Thrust (MHT) is a décollement under the Himalaya Range. This thrust fault follows a NW-SE strike, reminiscent of an arc, and gently dip towards the north, beneath the region. It is the largest active continental megathrust ...

, it being of

continental crust Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called '' sial'' be ...

does not

subduct Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

, rather, it plows into the Eurasian Plate. This process severely deforms the Eurasian Plate, uplifting the crust, forming the

Tibetan Plateau The Tibetan Plateau (, also known as the Qinghai–Tibet Plateau or the Qing–Zang Plateau () or as the Himalayan Plateau in India, is a vast elevated plateau located at the intersection of Central, South and East Asia covering most of the Ti ...

. The force of the Indian Plate converging pushes the Tibetan Plateau east, towards the

, forming another zone of collision. This collision and resulting crustal deformation of the Eurasian Plate is accommodated by the Xianshuihe fault system, Kunlun Fault,

Altyn Tagh fault The Altyn Tagh Fault (ATF) is a 2,000 km long, active, sinistral (left lateral) strike-slip fault that forms the northwestern boundary of the Tibetan Plateau with the Tarim Basin. It is one of the major sinistral strike-slip structures that t ...

, and

. The presence of active faults in Sichuan makes the region vulnerable to damaging earthquakes. The deadly 2008 Sichuan earthquake occurred due to a

thrust fault A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If ...

rupture on the

Effects

The earthquake has resulted in 196 people dead, 24 missing, at least 11,826 injured with more than 968 seriously injured as of 5:00 PM (UTC+8h, April 20). Sichuan provincial government has held the 3rd press conference on April 21, reported that the earthquake has resulted in 186 people dead, 21 missing, 11248 injured and 852 of them seriously as of 2:00 PM (UTC+8h, April 21), this is still the latest official report. Several townships suffered major damage, and many old buildings in Lushan collapsed. The electricity service was interrupted, and the electricity grids in the counties of Baoxing, Lushan, and

Tianquan Tianquan County () is a county of Sichuan Province, China. It is under the administration of Ya'an City. In 1950, the county bore witness to the Battle of Tianquan, which resulted in the communists defeating the nationalists Nationalism i ...

disintegrated. Telecommunication was interrupted in part of Ya'an. The Chengdu–Ya'an and Ya'an–Xichang sections of the

G5 Beijing–Kunming Expressway The Beijing–Kunming Expressway (), designated as G5 and commonly referred to as the Jingkun Expressway () is an expressway that connects the cities of Beijing, and Kunming, in Yunnan province. It is in length. As of 2018, the expressway has ...

were reserved exclusively for vehicles for rescue purpose and closed to other vehicles. The Xiaojin section () of Sichuan Provincial Highway 210 between Baoshan () and Lushan was interrupted. A debris dam appeared in Jinjixia () of the Yuxi River () in Lushan. 2 volunteers were injured seriously in a traffic accident on the way to Lushan. However, around 60 giant pandas in the BiFengXia National Nature Reserve in Ya'an, were left unharmed by the devastating earthquake.

Lushan

The epicenter was located in Lushan. As of April 21, it was reported that 120 people died, 578 people were seriously injured, 5537 slightly injured, 278 saved from the ruins, and 3 still missing in Lushan County. The electricity grid disintegrated, and there were no water and gas services. According to

China News Service China News Service (CNS; ) is the second largest state news agency in China, after Xinhua News Agency. China News Service was formerly run by the Overseas Chinese Affairs Office, which was absorbed into the United Front Work Department of the ...

, "100%" of houses in the 9 towns and townships and in the county seat were damaged.

Baoxing

As of April 21, it was reported that 24 people died, 2500 were injured, and 19 missing in Baoxing County. The electricity, water, and gas services were interrupted in the county seat. Most of houses in the county seat of Baoxing were uninhabitable. Water, medicines, and tents were urgently needed. Some rescuers had had to walk to Baoxing because major roads to there were cut off. On April 22, it was reported that the access to the county seat of Baoxing had been restored.

Rescue efforts

About 8,000 soldiers from the

People's Liberation Army The People's Liberation Army (PLA) is the principal military force of the China, People's Republic of China and the armed wing of the Chinese Communist Party (CCP). The PLA consists of five Military branch, service branches: the People's ...

were sent into the stricken area in the immediate aftermath of the earthquake, as well as 1,400 provincial rescue workers and 120 support vehicles. Also, 180 doctors from a Chinese emergency response team and search-and-rescue dogs were dispatched, with volunteers mobilized from other parts of the country. Chinese Premier

Li Keqiang Li Keqiang (born 1 July 1955) is a Chinese politician who is the outgoing premier of China. An economist by profession, Li is head of China's executive branch as well as one of the leading figures behind China's Financial and Economic Affa ...

toured the area and emphasized the need for quick action. Officials warned that regional rainfall and aftershocks were factors complicating the rescue efforts, with potential secondary effects like additional

landslide Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated slope failures, mudflows, and debris flows. Landslides occur in a variety of environmen ...

s and further building collapses being concerns. Impassible roads and damaged communications infrastructure posed substantial challenges to rescue efforts.

Hong Kong donations controversy

Hong Kong chief executive, Leung Chun-ying, put forward a proposal to the Legislative Council to donate HK$100m ($13m) to the Sichuan provincial government for relief efforts. However, the government motion was vehemently opposed by legislators, in particular pan democrats, who feared that the local government would misuse the funds destined to help with earthquake relief efforts. Apparent signs of misappropriations or misuse by local officials of $HK9 billion donated after the earthquake in 2008 was cited as one major concern. The proposal failed to win support of Hong Kong people. A civic campaign was started online to try to stop earthquake donations falling into the hands of corrupt officials; and the liberal ''Apple Daily'' highlighted embezzlement scandals on the mainland. To satisfy the legislature, the Hong Kong government was forced to donate the money to registered Hong Kong non-governmental organisations.

Day of mourning

On April 25, the provincial government of Sichuan announced that April 27 (seven days after the occurrence of Lushan earthquake) would be the day of mourning for those that passed in earthquake. Public entertainment was forbidden, and the sound of siren wailed for 3 minutes to mourn the loss of earthquake. The domestic media also mourned the passed in different ways.

Baidu Baidu, Inc. ( ; , meaning "hundred times") is a Chinese multinational technology company specializing in Internet-related services and products and artificial intelligence (AI), headquartered in Beijing's Haidian District. It is one of the l ...

changed its background of the page to black. The social media also developed a special feature about the Lushan earthquake.

References

External links

* {{Earthquakes in China 2013 earthquakes

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

Earthquakes in Sichuan April 2013 events in China Buried rupture earthquakes