Haiyuan Earthquake (1920): China's Great Ningxia Earthquake

The Haiyuan earthquake struck northwest China on the evening of 16 December 1920, with its epicentre in Haiyuan County, then part of Gansu province and now in the Ningxia Hui Autonomous Region. Its magnitude is estimated at about 7.8 to 8.0, and it killed an estimated 200,000 to 270,000 people, many of them buried by enormous landslides in the region’s loess hills. It is one of the deadliest earthquakes in recorded history.

Background

The Haiyuan region lies on the north-eastern edge of the Tibetan Plateau, where the slow collision of the Indian and Eurasian tectonic plates pushes crustal blocks against each other. The Haiyuan Fault, a long strike-slip fault where the ground on either side moves sideways, runs through the area and has produced large earthquakes in the past.

Much of the landscape is covered by loess, a fine yellow soil laid down by wind over hundreds of thousands of years. Loess is easy to dig and fertile when watered, and many families in the region lived in cave homes cut into loess hillsides. However, it can lose its strength suddenly when shaken, which makes it extremely dangerous in an earthquake.

In 1920 China was politically divided. The Xinhai Revolution of 1911 had ended imperial rule, but the Beijing government had little real control over distant provinces, which were run by regional military leaders. Northern China was also suffering a severe drought and famine in 1920 and 1921.

The earthquake

The main shock struck at about 8 p.m. local time on 16 December 1920, a winter evening when most people were at home. Violent shaking lasted for several minutes, according to survivors’ accounts. Towns and villages across Haiyuan, Guyuan, Xiji, Jingning and other counties were devastated.

The earthquake ruptured the surface along the Haiyuan Fault for more than 200 km. In places the ground was offset sideways by several metres, and geologists later measured displacements of up to about 10 metres. Roads, walls, irrigation channels and field boundaries were broken and shifted.

The shaking was felt over a vast area of China, and it was recorded by seismographs around the world. Aftershocks continued for months and, according to some accounts, for years, adding to the fear and suffering of survivors.

Landslides and destruction

The most destructive effect was the collapse of loess slopes. Hundreds of landslides, some several kilometres long, swept down hillsides and buried villages in the valleys below. In some places entire communities disappeared under the soil. Landslide debris also dammed rivers and streams, creating new lakes, some of which still exist.

Cave dwellings dug into loess cliffs collapsed on their occupants, and houses of earth and timber fell in. Because the earthquake struck in mid-winter, many survivors who had lost their homes then died of cold and hunger in the following weeks. Livestock, food stores and fuel were also lost, making it hard for communities to recover.

Much of the population of the region was Hui, Chinese-speaking Muslims, alongside Han Chinese, and both communities suffered enormous losses. Some counties lost a large share of their inhabitants.

A region already in crisis

The earthquake struck during one of the hardest periods in modern Chinese history. A severe drought in 1920 had caused crop failures across several northern provinces, and the resulting North China famine of 1920 and 1921 is estimated to have killed around half a million people. Relief organisations and foreign aid were stretched, and in 1921 several famine-relief groups came together as the China International Famine Relief Commission.

Political conditions made matters worse. Gansu and neighbouring regions were controlled by local military commanders whose loyalty to the government in Beijing was uncertain. Roads were few, and many communities depended almost entirely on what they could grow. When the earthquake destroyed homes, grain stores and animals in the middle of winter, there was little outside help to fall back on.

Relief and investigation

Help was slow to arrive. The region was remote, transport was poor, and the weak central government was preoccupied with political turmoil and with famine elsewhere in the north. Local officials, religious organisations and foreign missionaries provided what relief they could, and international famine-relief bodies also sent aid.

In 1921 two Americans, the writer Upton Close and the journalist Elsie McCormick, travelled through the affected area to see the damage for themselves. Their article “Where the Mountains Walked”, published in National Geographic Magazine in May 1922, brought the scale of the landslides to an international audience and gave the disaster one of its best-known descriptions.

Scientific importance

The Haiyuan earthquake has become one of the most studied earthquakes in China. Its long surface rupture provides geologists with a clear example of how large strike-slip faults behave. From the 1980s onward, joint Chinese and international field studies mapped the rupture in detail, measuring offset streams, walls and terraces along its length. These studies helped confirm that the fault accommodates part of the eastward movement of crust squeezed out of the Tibetan Plateau. Studies of the fault have helped scientists estimate how often such earthquakes recur and how fast the crust is moving in this part of Asia.

The disaster also highlighted the special danger of earthquakes in loess regions, a lesson confirmed in China by the even deadlier Shaanxi earthquake of 1556, which also caused mass deaths in loess cave dwellings. Later Chinese building and land-use policies in the region have taken landslide risk into account.

Myths and facts

The disaster is often confused with another great earthquake in the same province. On 23 May 1927 the Gulang earthquake struck Gansu farther to the west, killing an estimated 40,000 people. Older English-language books sometimes call both events the “Kansu earthquake”, which has caused muddled dates and figures.

It is sometimes said that the Haiyuan earthquake was the deadliest in Chinese history. That distinction is usually given to the 1556 Shaanxi earthquake, and the Tangshan earthquake of 1976 had an officially reported death toll of a similar order to Haiyuan. All three disasters show how dangerous large earthquakes have been in densely settled parts of northern China.

The landslides left lasting marks on the landscape. Some valleys dammed by collapsing hillsides became permanent lakes, and scientists still use the scars of the 1920 slides to study how loess slopes fail during earthquakes.

By the numbers

Timeline

• 1920: Drought and famine affect much of northern China.
• 1920, 16 December, about 8 p.m.: The main earthquake strikes Haiyuan and surrounding counties.
• 1920, late December: Survivors face freezing temperatures; many die of cold and hunger.
• 1921: Upton Close and Elsie McCormick travel through the affected region.
• 1922, May: National Geographic publishes “Where the Mountains Walked”.
• 1958: The Ningxia Hui Autonomous Region is created, and Haiyuan becomes part of it.

Why it matters

The Haiyuan earthquake was one of the worst natural disasters of the twentieth century, killing hundreds of thousands of people in a remote and poor region. It revealed how deadly loess landslides could be and remains a key case for scientists studying large earthquakes and their hazards in Asia.