Typical earthquakes
⑴ Xingtai Earthquake in Hebei
From March 8 to March 29, 1966, one after another earthquakes over 6 or 7 magnitudes
happened. The first of all the earthquakes, was an earthquake of 6.8 magnitudes, happened
to the East of Longyao County, Xintai, Hebei. Thereafter, five earthquakes of over scale 6
took place successively. On March 22, the most serious earthquake, which was 7.8 in
magnitude scale, took place in the South-Eastern part of Ningjin County. Because of the
soft soil and high underground water level in the earthquake area, the earthquake caused
tremendous damages to large areas.
More than 142 counties were affected by the 6.8 magnitude earthquake
and more than 136 counties were severely damaged by the 7.2 scale earthquake. The
earthquake felt areas included Duolun (in Inner Mongolia) in the North, Yantai (in
Shandong Province) in the East, Nanjing (in Jiangsu Province) in the South and Tongchuan
in the West. The earthquake caused the deaths of 8182 people, the injuries of 51395
people. More than 2 million rooms and 86 bridges were destroyed. Altogether, more than 115
fires were caused by the earthquake and burned more than 16 people. The number of burned
houses was 153. Avalanches happened in 300 places in Xingtai and nearby, which caused 22
consequent fires.80 hektare of natural mountains were burned The ground was split and
underground water was sprouted out. Some bridges over Puyang River were most seriously
damaged. As of Da Xin Village Bridge, the top was removed from the pier 1.8 meters
Southwards and the traffic broke off. Even in Tianjin and Zhuo County, the generators
stopped for a short time. There were also severe damages in the West part of Shi
Jiazhuang, Xiyang in Shangxi Province. The Central Government paid much attention to the
earthquake, immediately ordering the army to rescue the people from the catestrophe.
Premier Zhou Enlai arrived at the quake-stricken area on March 9th in spite of the threat
of aftershock. 94 medical teams and 7115 medical personnel were dispatched there too.
⑵ Daguan Earthquake in Yunnan
On May 11, 1974, an earthquake of 7.1 magnitude happened. There was a
strong sense of shock in an area of about 400,000 square km. The earthquake killed 1423
people, hurt 1600 people, damaged 66,000 houses, of which 28,000 houses cracked down. But
the wooden-framed houses were not damaged at all in the central earthquake area. It also
caused the mountains to avalanche and the ground to split. It ruined the roads, fields,
penstocks and swallowed villages. The largest avalanche thronged to the opposite bank of
the crook and formed a dam, which was as high as 30 meters. The crook valley was
immediately changed into a reservoirs.
⑶ Haicheng Earthquake in Liaoning
On February 4, 1975, there happened an earthquake of 7.3 magnitude,
covering an area of 760 square kilometers. It was a crowded industrial area. Thanks to the
successful earthquake forecast, the largest earthquake in the area in the history caused
comparatively fewer damages. Most of the people left their houses and fewer people were
killed than expected. The dead and hurt greatly decreased to 29,579 in number, 0.3 % of
the total population in this area. 2041 people were dead. The economic loss was about 810
Millions yuan , calculated on the damages of infrastructure, instruments and equipment and
others. The sand-sprout hole was 2.5 in diameter. There was an earthquake fracture zone of
5.5 kilometers long in the road. The width is 40 meters. The damaged coverage in Yingcou
City occupied 53.1% of the total area. The government organized and arranged emergent
rescues. It is presumed that the number of the dead and hurt would have been 150,000 in
total and the economic loss up to 50 Billions yuan if there had no forecast.
⑷ Longling Earthquake in Yunnan
On May 29, 1976, in Longling County in the West part of Yunnan happened
two strong shocks one after another. The first took place at 20:23'18. It was of 7.3
magnitudes. The second was of 7.4 magnitude, occurring at 22:0'23''. The shock belonged to
swarm-type earthquake. Aftershocks occurred with high intensity and frequency. Each shock
had two meizoseismal regions. During the period from May 29 to the end of the year, there
happened 2477 earthquakes of 3 plus magnitude, among which there was 19 earthquakes of 4.7
and/or 5.9, one of 6.2, 7.3 and 7.4 respectively. This earthquake affected Baoshan
District, Yunnan, Lincang District, 9 counties in Dehong municipality at different levels.
98 people died, 451 people were heavily hurt, 1991 were slightly hurt. There were 420,000
houses cracked down or ruined. The damage coverage was about 1883 square kilometers.
Landslips caused by the shock resulted in severe damages, including damaging 180 farm
houses, 3900 hectares of field, farm, forests and tea gardens ruined, 1126 canals and one
hydroelectric station with the capacity of 240kw and three with the capacity of below 20
kw, 185 km of highway. The landslides covered an area of 780,000 kilometers. The typical
feature was shallow landslides.
⑸ Tangshan Earthquake in Hebei
On July 28, 1976, an earthquake of 7.8 magnitude occurred in Tangshan
City. The epicenter is the City center itself. This was a rare city earthquake. Just in a
second, a city with one million people was razed to the ground. The people and the city
suffered much from the earthquake. Even Beijing and Tianjin were severely affected. The
damage coverage is above 30,000 kilometers. The shock could be felt in 14 provinces,
cities and municipalities, one-third of the country territory. The earthquake took place
at mid-night. Most of people couldn't take any action and were buried in the ruins and
relics. The mizoseismal regions covered an area of 47 square km at the two sides of
Jing-Shan railway, in which all buildings were completely ruined. One 8-km-long and
30-meter-wide slip cut through courtyards, houses, roads and canals. In the earthquake
area and nearby, there appeared many crack zones, watersprouts and sandboils, hole blow,
gravity landfalls, rolling stones, side slope, foundation subsidence, Karst cave downdrop
and collapses of the hollow areas etc., causing 242,000 people to die and 164,000 heavily
injured. Just in Tangshan, 1700 people suffered the disability for his rest of life. The
direct economic loss was 540 million yuan including the damages of 530 houses and 1479
square kilometers of public houses. Water, power, communication and traffic were
completely destroyed. All the mines stopped, and the infrastructure including hospitals
and pharmaceutical equipment were completely destroyed.
⑹ Songfan-Pingwu Earthquake in Sichuan
It was August 16, 1976 when an earthquake of 7.2 magnitude happened in between
Songfan-Pingwu areas. The earthquake belongs to swarm-type earthquake. Following the main
earthquake were the shocks of 6.7 magnitudes on August 22 and the shock of 7.2 magnitudes
on August 23. The earthquake could be felt in a large surrounding area including Gaotai
(in Gansu Provice) in the West; Kunming (in Yunnan Province) in the South; Hohehot (in
Inner Mongolia) in the North and Changsha (in Hunan Province) in the East, with the
longest radius of 1150 km. The continuous rainstorms caused the mountain avalanches,
collapses and mud-rock flows, which, in turn, caused bad damages to fields, roads and
riverbeds. The communication with outside was cut off. A lot of farms were destroyed. The
loss in grain production amounted to 5 million kg and more than 2000 horses were killed.
Because the shock took place in scarcely inhabited areas and because of the earthquake
forecast and evacuation of the people, only 800 people were killed or injured in this
shock. 600 people suffered slight injuries from avalanches, explosions and rolling rocks.
This earthquake also caused other loss in social and economic aspects.
⑺ Shangyi Earthquake in Hebei
At 11 o'clock on January 10, 1998, an earthquake of 6.2 magnitudes took
place, which caused horrible life losses and economic damages, and ranks among the most
serious earthquakes of china in this year. The result of the earthquake was terrible, more
than 19 cities and nearly 170,000 people's life in Zhangbei, Shangyi, Wanquan and Kangding
were affected. 49 people were killed and 11439 people were injured. The death toll
occupied 83.9% of the total figure in the same kind of disasters occurred in our country
in that year. Because the structure, the location and the quality of the house all had
problems in resisting earthquake, the earthquake damaged most of them. The economic loss
reached up to 794 Million yuan, which took up 44.6% of the total economic loss in that
year. The neighboring county also suffered great economic loss.
|
