What was the Tangshan earthquake of 1976?
At 3:42 a.m. on July 28, 1976, a magnitude 7.8 earthquake hit the sleeping city of Tangshan, in northeastern China.
Where is the epicentre of the Tangshan earthquake?
Its epicentre was located in the southern part of the city of Tangshan, some 9 miles (15 km) above the earthquake’s focus, and shaking was felt more than 680 miles (1,100 km) away in all directions. Later that same day, a major aftershock (magnitude 7.1) occurred in the city of Luanxian, some 43 miles (70 km) to the northeast.
How well was China prepared for the Tangshan earthquake?
Although afterwards some early signs were reportedly spotted in various localities, the Tangshan earthquake was not predicted with any accuracy through this system. The region’s preparedness was therefore low. The Tangshan earthquake is regarded as the deadliest earthquake in the 20 th century and one of the most deadliest in recorded history.
How did the Tangshan earthquake take place?
Earthquakes measuring 4.5 Ms to 4.7 Ms occurred in 2012, 2016 and 2019. On 12 July 2020, a 5.1 Ms strike-slip earthquake struck the northern part of the Tangshan Fault. It produced its own sequence of aftershocks that ended on 17 July 2020. The earthquake only caused minor damage to buildings in Tangshan.
What time did the Tangshan earthquake occur?
3:42 a.m.At 3:42 a.m., an earthquake measuring between 7.8 and 8.2 magnitude on the Richter scale flattens Tangshan, a Chinese industrial city with a population of about one million people.
How long did the 1976 Tangshan earthquake last?
As almost everyone was asleep when the earthquake struck, it led to a significantly greater loss of life. The earthquake lasted for 23 seconds and flattened almost 90 per cent of buildings in Tangshan.
What happened in the 1976 Tangshan earthquake?
At 3:42 a.m. on July 28, 1976, a magnitude 7.8 earthquake hit the sleeping city of Tangshan, in northeastern China. The very large earthquake, striking an area where it was totally unexpected, obliterated the city of Tangshan and killed more than 240,000 people—making it the deadliest earthquake of the 20th century.
When was the biggest earthquake in China?
The most powerful Sichuan earthquake on record was in May 2008, when a magnitude 8.0 quake centred in Wenchuan killed almost 70,000 people and caused extensive damage.
What is Tangshan known for?
It is China's largest steel-producing city. Tangshan is also called the "porcelain capital of North China."
What was the worst earthquake in China?
China has been the location of some of the most deadly earthquakes in history. The deadliest was the 1976 Tangshan earthquake with 300,000+ deaths. Earthquakes in the loess plateau where residents lived in yaodong caves tended to have big casualties, including the 1303 Hongdong and 1920 Haiyuan earthquakes.
What is the deadliest earthquake?
The most deadly earthquake in history was in Shaanxi, China in 1556. It's estimated to have killed 830,000 people. This is more than twice that of the second most fatal: the recent Port-au-Prince earthquake in Haiti in 2010. It's reported that 316,000 people died as a result.
What causes the earth to shake?
The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause the shaking that we feel.
How much damage did the Tangshan earthquake cause?
Economic losses were estimated to be about 10 billion yuan, but Tianjin city alone suffered about 7.5 billion Y in direct and indirect damages, therefore even this figure is probably inaccurate.
How long did the 1980 Italy earthquake last?
On the evening of November 23rd 1980, a devastating earthquake hit southern Italy claiming almost 3,000 lives. tI lasted no more than a minute, but it changed the area forever.
How much damage did the Tangshan earthquake cause?
Economic losses were estimated to be about 10 billion yuan, but Tianjin city alone suffered about 7.5 billion Y in direct and indirect damages, therefore even this figure is probably inaccurate.
How long did it take to rebuild Tangshan after the earthquake?
ten yearsThe earthquake recovery in Tangshan officially came to an end when the permanent housing recovery was completed in October 1986. This process took a little more than ten years, twice as long as the original five-year target set forth in the 1976 recovery plan.
What year was the Tangshan earthquake?
Yong, Chen, et al. The Great Tangshan Earthquake of 1976: An Anatomy of Disaster. New York: Pergamon Press, 1988.
How long did the Tangshan earthquake last?
When the 7.8 magnitude earthquake struck Tangshan, more than 1 million people were sleeping, unaware of the impending disaster. As the earth began to shake, a few people who were awake had the forethought to dive under a table or other heavy piece of furniture, but most were asleep and did not have time. The entire earthquake lasted approximately 14 to 16 seconds.
What was the biggest earthquake in 1976?
Jennifer Rosenberg. Updated September 25, 2019. At 3:42 a.m. on July 28, 1976, a magnitude 7.8 earthquake hit the sleeping city of Tangshan, in northeastern China. The very large earthquake, striking an area where it was totally unexpected, obliterated the city of Tangshan and killed more than 240,000 people—making it the deadliest earthquake ...
What was the intensity level of the 1976 earthquake in Tangshan?
The 7.8 earthquake that hit Tangshan was given an intensity level of XI (out of XII).
Why is Tangshan called the brave city of China?
In the succeeding decades, the experiences of Tangshan have been used to improve earthquake predicting capabilities and the provision of medical support in major disasters.
What animals were running around in Baiguantuan?
One thousand chickens in Baiguantuan refused to eat and ran around excitedly chirping. Mice and yellow weasels were seen running around looking for a place to hide. In one household in the city of Tangshan, a goldfish began jumping wildly in its bowl.
What caused the collapse of the bridges?
The foundations of bridges gave way, causing the bridges to collapse. Railroad lines bent. Roads were covered with debris and were riddled with fissures.
Where did the Tangshan earthquake occur?
Tangshan earthquake site. The rupture occurred under the southern part of the city, and propagated northeastward on a fault that runs through the middle of the city. The maximum intensity was "XI" (eleven) on the 12-degree Chinese scale.
What year was the Tangshan earthquake?
242,419. The 1976 Tangshan earthquake ( Chinese: 唐山大地震; pinyin: Tángshān dà dìzhèn; lit. 'Great Tangshan earthquake'), also known as the Great Tangshan earthquake, was a natural disaster resulting from a magnitude 7.6 earthquake that hit the region around Tangshan, Hebei, People's Republic of China on 28 July 1976, at 3:42 in the morning.
What is the name of the railway that runs from Tianjin to Tanggu?
The Beijing–Shanhaiguan Railway (built in 1887) is a double-track Class I trunk line that runs from Beijing southeast to Tianjin and Tanggu, then turns northeast to cross the Yongdingxin River and its estuary to run to Ninghe and then Tangshan. From Tangshan it continues northeast and then east to Chengli, and then to Qinhuangdao and Shanhaiguan. This is the principal connection of Beijing, Tianjin, and Tangshan to the seaports, and to Northeast China. The Tongxian to Tuozitou (within modern-day Luan County) Railway (built in 1976) is a single-track Class I trunk line that runs east from the eastern outskirts of Beijing to where it meets the Beijing to Shanhaiguan line northeast of Tangshan (near the epicenter of the M 7.1 quake). All of this was built "with no consideration for earthquake resistant design", although some "earthquake resistance measures" for large and medium bridges were applied following the 1975 Haicheng earthquake .
How did the earthquake affect the railways?
These vital arteries (and other railways and branch lines) were seriously damaged by the earthquakes, mainly in the areas of intensity IX or greater shaking. (This includes a large area around Tangshan quake, and areas around Ninghe and Luanhsien following the M 6.9 and M 7.4 aftershocks.) At the time of the main quake there were 28 freight trains and seven passenger trains traveling on the Beijing–Shanhaiguan line in the affected area; seven freight trains and two passenger trains derailed due to derangement of the rails, mostly south of Tangshan where the line was built on loose alluvium, diluvium, and occasional stretches of loose sand. In many of these cases – and also similar cases northeast of Tangshan, and on the Tongxian–Tuozitou line east of Fengrun – the railway embankment slumped due to weak soils. In other cases the embankment held, but transverse compression of the rails caused them to buckle.
What was the maximum intensity of the Tangshan earthquake?
The maximum intensity of the earthquake was XI ( Extreme) on the Mercali scale. In minutes, eighty-five percent of the buildings in Tangshan collapsed or were unusable, all services failed, and most of the highway and railway bridges collapsed or were seriously damaged.
Where is the Tongxian to Tuozitou line?
The Tongxian to Tuozitou (within modern-day Luan County) Railway (built in 1976) is a single-track Class I trunk line that runs east from the eastern outskirts of Beijing to where it meets the Beijing to Shanhaiguan line northeast of Tangshan (near the epicenter of the M 7.1 quake).
How did the 1975 earthquake affect China?
The 1975 Haicheng earthquake (about 400 km [250 miles] northeast of Tangshan) was widely hailed as the first (and, by mainstream seismologists, the only) successful prediction of a major earthquake, demonstrating both that earthquakes could be predicted, and that the Chinese were successfully doing so. The surprisingly light death toll – initial reports were of "very few people killed", but later determined to be a modest 2,041 —for this magnitude Ms 7.5 quake, attributed to the precautionary measures taken following a definite short-term prediction, was proclaimed as a demonstration of the superiority of China's socialist system, and incidentally a validation of the Chinese methodologies. However, it was later determined that the most important factor in anticipating the Haicheng earthquake was the extended series of significant foreshocks ("powerful messages from nature" ), and the low casualty rate was due largely to the time of day, hitting in the early evening when most people were neither at work nor asleep.
Overview
The 1976 Tangshan earthquake (Chinese: 唐山大地震; pinyin: Tángshān dà dìzhèn; lit. 'Great Tangshan earthquake ') was a Mw 7.6 earthquake that hit the region around Tangshan, Hebei, China, at 3:42 a.m. on 28 July 1976. The maximum intensity of the earthquake was XI (Extreme) on the Mercalli scale. In minutes, 85 percent of the buildings in Tangshan collapsed or were rendered …
The earthquakes
The Tangshan earthquake was composed of two main shocks. The first struck at 3:42:56 in the morning (local time), approximately 12 km under the southern part of Tangshan. The magnitude was initially estimated at 8.1, subsequently recalculated to be 7.6 on the standard Mw scale. However, that scale measures only the total energy released by an earthquake, and earthquakes vary in how much of that energy is converted to seismic shaking. The Tangshan quake, being re…
Damage
The damage done by an earthquake depends primarily on two factors. First, the intensity of shaking, which depends mainly on the magnitude of the earthquake rupture, the distance from the epicenter, and the nature of the local soil and topography, with soft soils (e.g., sediments and fill) more likely to amplify the intensity and duration of the shaking. Second, the design and construction of t…
Death toll
The official report claimed 242,769 deaths and 164,851 serious injuries in Tangshan, but when take into account the "missing", the injured who later died and the deaths in nearby Beijing and Tianjin, scholars accepted at least 300,000 died, making it the deadliest earthquake in China and among the top disasters in China by death toll. Unofficial estimates of the death toll varied widely, and ge…
Political aspects
The remarkably low death toll of the Haicheng earthquake the previous year – initially said to be fewer than 300, much later estimated at a still very modest 2,041 – had been credited to measures taken in response to an accurate and timely prediction. This was touted as demonstrating the validity of the Chinese methods of earthquake prediction (including inspiration from "Mao Zedong Thought" ) and "the superiority of our country's socialist system!"
Geology
Tangshan lies at the northern edge of the Beijing-Tianjin-Tangshan Plain, an alluvial plain that stretches from Beijing to the Sea of Bohai. This plain – the northeastern corner of the great North China Plain – is where sediments eroded from the Yanshan mountains to the north have filled in the ancient Sea of Bohai, with Tangshan near where the shore was about 4,000 years ago. To the sout…
Question of prediction
Whether the Tangshan earthquake was predicted has had considerable political as well as seismological significance.
The 1975 Haicheng earthquake (about 400 km [250 miles] northeast of Tangshan) is regarded by seismologists as the only successful prediction of a major earthquake, although no mechanism has been proposed to explain this prediction, and no successful predictions have been achieve…
Comparison
Comparison of the Tangshan death toll – officially 242,419 —with other earthquake disasters is problematical because of uncertainty in the statistics. For example, the 1556 Shaanxi earthquake (estimated magnitude of ~8) is generally said to have been the deadliest earthquake disaster in history, with 830,000 deaths, based on Chinese historical records. However, a Chinese language source argues for only 530,000 deaths from the earthquake itself, with the larger number being t…