Smith, Greg dot com

On May 12, 2008 a 7.8 earthquake hit central China.

The epicenter was 80 kilometres west-northwest of Chengdu, the capital of Sichuan, with a depth of 19 kilometres. The earthquake was felt as far away as Beijing (1,500 kilometres away) and Shanghai (1,700 kilometres (1,056 mi) away), where office buildings swayed with the tremor. The earthquake was also felt in nearby countries.

Official figures... state that 69,197 are confirmed dead, including 68,636 in Sichuan province, and 374,176 injured, with 18,222 listed as missing. The earthquake left about 4.8 million people homeless, though the number could be as high as 11 million. It is the deadliest and strongest earthquake to hit China since the 1976 Tangshan earthquake, which killed at least 240,000 people. Approximately 15 million people lived in the affected area.

Strong aftershocks, some exceeding magnitude 6, continue to hit the area even months after the main quake, causing new casualties and damage.

As bad as the "Great Sichuan Earthquake" of May 2008 quake was, it wasn't the deadliest earthquake in Chinese history. In 1552 a quake with an estimated magnitude of between 8.0 and 8.3 hit roughly the same region, killing an estimated 830,000 people.

Two of the earth's major tectonic plates are grinding against each other in Central China. The Indian plate is being pushed up above the Eurasian plate. The result is that the Himalaya mountain range is still rising, but as they rise up over the Asian plate the fault line in Central China frequently suffers violent earthquakes.

Central China's quakes aren't just frequent and violent, they are especially deadly as well. China not only has many of the world's largest and densest population centers, it has had that density for centuries. Violent earthquakes (or floods or any other natural disaster) affect large numbers of people.

Analysis of the fault lines leads modern researches to estimate that the 1556 quake had a magnitude of 8.0. The rupture occurred during the reign of the Jiajing Emperor of the Ming dynasty. Therefore, in Chinese historical record, this earthquake is often referred as the Jiajing Great Earthquake. In some cities, every single building and home was demolished, killing more than half the residents of the city, with a death toll estimated in the tens of thousands. In some places, 20-metre (66 ft) deep crevices opened in the earth. Destruction and death was everywhere, affecting places as far as 500 kilometres (310 mi) away from the epicenter. The earthquake also triggered landslides, which contributed to the massive death toll.

Following the earthquake, aftershocks continued several times a month for half a year.

Perhaps the major contributor to the staggering 830,000 person death toll of the 1556 quake was that people in the region lived in terraced homes cut into soft clay hillsides along the river valleys. These hillsides slipped and hundreds of thousands died in landslides when their homes collapsed.

The official Chinese government annals of the time described the quake this way:

In the winter of 1556, an earthquake catastrophe occurred in the Shaanxi and Shanxi Provinces. In our Hua County, various misfortunes took place. Mountains and rivers changed places and roads were destroyed. In some places, the ground suddenly rose up and formed new hills, or it sank in abruptly and became new valleys. In other areas, a stream burst out in an instant, or the ground broke and new gullies appeared. Huts, official houses, temples and city walls collapsed all of a sudden. ” —This quotation is from a translation of a Chinese study of historical earthquake. 賀明靜編著，(1990年)，《（1556年）華縣地震災害研究》，西安：陜西人民出版社，頁92