Earthquake Hazard in Eastern China

Source: Global Seismic Hazard Assessment Program

Nature of Seismic Hazard in Sichuan

Yunnan - Sichuan. 32 earthquakes with Ms > 7 1500 years ago (Gu, 1983; Ma, 1989).

Two events Ms > 8 caused a great number of casualties and significant economic damage.

Earthquakes in this region are characterized by shallow strike-slip faulting (focal depths between 10 and 15 km; Allen et al., 1989; Zhou et al., 1983).

The seismicity of the region may be divided into two sub-regions (figure 3): the western Sichuan -

eastern Yunnan sub-region (4)

and the western Yunnan sub-region

Sichuan EarthquakesEarthquakes with magnitude greater than 7.0

Name Date Magnitude EpicenterGarzê earthquake 1786 7.8 Dardo and Luding County

Garzê earthquake 1786 7Luding County in the Garzê Tibetan Autonomous Prefecture

Luhuo Earthquake 1816 7.5Luhuo County in the Garzê Tibetan Autonomous Prefecture

Xichang earthquake 1850 7.5 Xichang in the Liangshan Yi Autonomous Region Diexi earthquake 1933 7.5 Diexi, Mao County

Dardo Zheduo earthquake 1955 7.5 Dardo and Zheduo Dyke Kangding earthquake 1955 7.5 Dardo County Luhuo earthquake 1973 7.9 Luhuo County Songpan-Pingwu earthquake 1976 7.2 Songpan-Pingwu County Sichuan earthquake 2008 8 Wenchuan County

Earthquakes with magnitudes between 6.0 and 6.9Name Date Magnitude Epicenter

Mabian earthquake 1935 6 Leshan in the Mabian Yi Autonomous County Huili earthquake 1955 6.75 Huili County and Yuzha Township Dardo Jiulong earthquake 1975 6.2 Dardo and Jiulong County Dawu earthquake 1981 6.9 Dawu County Garzê earthquake 1982 6 Garzê County Batang earthquake 1982 6.7 Batang County Yajiang earthquake 2001 6 Yajiang County Panzhihua earthquake 2008 6.1 Panzhihua

Number of School Age Children in High Earthquake Zones

Near Misses: Long Beach 1933 M6.370 schools collapsed. 120 damaged.

Schools Disproportionately affected: Field Act

Brief World History of School Collapses

(Below: Algeria1980, Ecuador 1976, China 1976,Peru 1974)

China’s school designs Chinese government revised the

building code after a major earthquake shattered Tangshan, claiming 240,000 lives in 1976.

The code was upgraded in 1989 and dubbed “the 89 standard.”

The 89 standard spells out detailed requirements for construction materials and design with a clear goal: Buildings should remain intact after minor shaking, receive repairable damage after moderate shaking, and remain standing after a major earthquake.  Fuxing (Left) school’s blueprint copied another school, but with some modifications.

A third floor was added, wall thickness was reduced to 24 centimeters from 37 centimeters, beam sizes were cut back, and a slab roof was installed instead of tile.

Most of the changes were made to save money.

Schools after the earthquake

Kindergarten in Chengdu

Juyuan Middle School in Dujiangyan city, near the earthquake's epicenter

Xinjian Primary School in Dujiangyan

Desks are seen in the ruins of a school destroyed Monday's earthquake, in Dujiangyan, in China's southwest Sichuan province Saturday May 17, 2008. China is to launch an investigation into why almost 7000 schoolrooms were destroyed and thousands of children killed in the earthquake, after accusations that the schools were shoddily built. (AP Photo/Greg Baker)

A student from another school looks through books found in the ruins of the Juyuan Middle School, in Dujiangyan, in China's southwest Sichuan province Saturday May 17, 2008. All but a handful of the school's 900 students were

killed when the school collapsed in Monday's earthquake.

Parents hold photos of their children during a memorial service for students killed in last week's earthquake at a primary school in Mianzhu, in China's southwest Sichuan province

Wednesday May 21, 2008. Parents held a memorial ceremony Wednesday for the more than 130 students killed when their school collapsed in a massive earthquake on May 12. (AP

Photo/Vincent Yu)

This kindergarten was among the many schools in the disaster region that suffered heavy structural damage.

Friday May 16, 2008, photo, distributed by the official Chinese news agency Xinhua, shows a dead student's hand holding a pen tightly in the debris site of Dongqi Middle School in

Hanwang Town of quake-hit Mianzhu City, southwest China's Sichuan province. (AP Photo/Xinhua, Liu Zhongjun)

Best Practices

Ye Zhiping is the principal of Sangzao Middle School Sichuan, saved thousands of his students.

Concerned over the structural integrity of school buildings, especially when facing an earthquake, he undertook special measures, collecting funds to strengthen existing structures.

As a result, all 2,323 students emerged unharmed.

This was in stark contrast to many other schools structures, which took a disproportionate damage compared to other buildings, leading to criticisms of government standards for educational facilities.

Some numbers and stuff from the UK’s Telegraph- May 12, 2008

• More than 107 people have already been confirmed dead in the quake, which caused buildings to sway thousands of miles away in Beijing, Taiwan and even Bangkok.

• reports of deaths came from Chongqing in Sichuan province, where two primary schools collapsed killing four students

• In Beijing, almost 1,400 miles away, buildings swayed for two minutes, while the effects were felt all over the country. In Shanghai, the Jinmao tower, the country's tallest building, was evacuated, along with many other of the city's skyscrapers, while residents reported feeling the tremors even in Taiwan and Hong Kong.

Some numbers and stuff from LA Times May 19th, 2008

• Officials said that at least 6,898 schoolrooms had collapsed in Sichuan province, where the quake was centered.

• Since 1990, when China’s seismic building codes were already established, thousands of schools have collapsed or sustained major damage, primarily in the countryside, according to research by Gao Jianguo, a professor at the Institute of Geology under the China Earthquake Administration in Beijing.

• In 2003, the latest year for which Gao compiled data, earthquakes destroyed or damaged more than 2,300 schools that served 425,000 students

• Gao said one major reason schoolhouses in rural China are vulnerable is that they have larger rooms lacking interior roof supports to accommodate class sizes of 70 to 80 students.

• In a northern rural district of Chongqing, about 200 miles from the epicenter, a four-story building collapsed at Center Elementary School, killing at least five students, according to local media accounts. Yet the apartments and houses behind the school were still standing.

• Lianshan Complete Primary School in Shaanxi province isn’t listed as a dangerous school. But its eight classrooms for 314 students and 20 teachers are in brick buildings with no concrete beams or pillars, said headmaster Chen Yudong.

Stats from MCEER

• A 7.9M earthquake struck Sichuan Province on Monday, May 12, 2008 • Aftershocks have been felt from Beijing, China to Bangkok, Thailand • 145 confirmed aftershocks above level 4, 23 above level 5, biggest 6.1 • Most damaging earthquake since the 1976 Tangshan disaster • View a detailed epicenter map • (June 13, 2008) Casualties continue to escalate; present official number is 68,620; 17,445

missing; 374,142 injured • Almost five million homeless • Public donations rise to 877 million yuan, $125 million US • Quake costs firms $9.5 billion, according to government • 70 billion yuan ($10.14 billion) reconstruction fund primarily for infrastructure • 6.0M aftershock Sunday, May 25 • 420,000 homes destroyed in Qingchuan County, Sichuan, following two aftershocks (4.5M and

5.7M) on Tuesday, May 27 • 160,000 people evacuated from Tangjiashan quake lake • Beichuan - an estimated 80% of buildings in the old town and 60% in the new town have been

destroyed • 143 aftershocks between May 27 noon and May 28 noon; total of 8,911 aftershocks since May

12 - according to China Seismological Bureau • approximately 30 'quake lakes' created from May 12th earthquake • more than 7,000 collapsed schoolrooms

• For more information http://mceer.buffalo.edu/infoService/disasters/china-earthquake-sichuan.asp

Links

• http://peer.berkeley.edu/pdf/NCREE-NewsLtr-ReconnaissanceReport-JW-0624.pdf

• A report prepared by was created by the National Center for Research of Earthquake Engineering in Taiwan (good images)

• http://peer.berkeley.edu/pdf/5-12-Wenchuan-mosalam-sitar-new.pdf

• provides some examples of good vs. poor performance, catalogs some reconstruction materials and procedures, and draws some conclusions about the elements that caused failure and collapse during the earthquake.

Shelby County and Sichuan

Sichaun Province

Area 485,000 km2 (187,000 sq mi)

Population 7,250,000 (2005)180 /km² (470 /sq mi)

Geography Mountainous

Schools Large rooms (80+)

number 1000+

Shelby County

Area 2,031 km² (784 sq mi)

Population 909,000 (2005)1,189/sq mi (459/km²)

Geography Flat

Schools Smaller rooms (30-40)

number 185

Gary’s ability to sum up.