The 1923 Renda earthquake occurred on March 24 at 20:40

local time Local time is the time observed in a specific locality. There is no canonical definition. Originally it was mean solar time, but since the introduction of time zones it is generally the time as determined by the time zone in effect, with daylight s ...

between the counties of Daofu and Luhuo in

Sichuan Sichuan is a province in Southwestern China, occupying the Sichuan Basin and Tibetan Plateau—between the Jinsha River to the west, the Daba Mountains to the north, and the Yunnan–Guizhou Plateau to the south. Its capital city is Cheng ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. The estimated 7.3 earthquake was assigned a maximum modified Mercalli intensity scale rating of X (''Extreme''). Severe damage occurred in Sichuan, killing an estimated 4,800 people.

Tectonic setting

Western

is situated at the edge of the

Tibetan Plateau The Tibetan Plateau, also known as the Qinghai–Tibet Plateau or Qingzang Plateau, is a vast elevated plateau located at the intersection of Central Asia, Central, South Asia, South, and East Asia. Geographically, it is located to the north of H ...

in a vast zone of complex continental deformation caused by the

collision In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great for ...

of the

Indian Plate The Indian plate (or India plate) is or was a minor tectonic plate straddling the equator in the Eastern Hemisphere. Originally a part of the ancient continent of Gondwana, the Indian plate broke away from the other fragments of Gondwana an ...

with the Eurasian Plate. As the thrusting of the Indian Plate beneath the Eurasian Plate along the

Himalayas The Himalayas, or Himalaya ( ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than list of h ...

continues, the continental crust within the Eurasian Plate is actively uplifted and thickened, forming the Tibetan Plateau. As there are no active thrust structures within the plateau, compression is accommodated by

strike-slip In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

motion along large structures including the

Altyn Tagh Fault The Altyn Tagh Fault (ATF) is a 2,000 km long, active, sinistral (left lateral) strike-slip fault that forms the northwestern boundary of the Tibetan Plateau with the Tarim Basin. It is one of the major sinistral strike-slip structures that to ...

, Kunlun Fault, Haiyuan Fault and

Xianshuihe fault system The Xianshuihe fault system or the Yushu-Ganzi-Xianshuihe fault system is a major active sinistral (left-lateral) Fault (geology)#Strike-slip faults, strike-slip fault zone in southwestern China, at the eastern edge of the Tibetan Plateau. It has ...

. Left-lateral

motion squeezes the crustal blocks of the Tibetan Plateau outwards, forcing it to move eastwards. Meanwhile, the strike-slip motion also results in east–west

extension Extension, extend or extended may refer to: Mathematics Logic or set theory * Axiom of extensionality * Extensible cardinal * Extension (model theory) * Extension (proof theory) * Extension (predicate logic), the set of tuples of values that ...

of the plateau, causing

normal fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

s to break within the thickened crust.

Earthquake

The

is a 1,400-km-long active left-lateral

strike-slip fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

that accommodate the strike-slip motion in the Tibetan Plateau. The fault is one of the largest active intracontinental geological structure in the world. Beginning in 1893, at least 350 km of the fault length has ruptured in large successive earthquakes with magnitudes 6.5 or larger. Going back to the year 1700 to present-day, the fault has ruptured its entire 1,400 km length during large earthquakes. A 60-kilometer-long

surface rupture In seismology, surface rupture (or ground rupture, or ground displacement) is the visible offset of the ground surface when an earthquake rupture along a Fault (geology), fault affects the Earth's surface. Surface rupture is opposed by buried rup ...

formed after the earthquake between Daofu and Renda. The immediate region around the surface rupture was also the

meizoseismal area The meizoseismal area in an earthquake is the area of maximum damage. For example, in the Charleston, South Carolina, earthquake of 1886, the meizoseismal area was an area about twenty by thirty miles stretching northeast between Charleston and ...

where the maximum intensity was X. The northwest extent of the rupture overlaps the eventual southeastern rupture zone of the 1973 Luhuo earthquake. Meanwhile, the farthest southeast rupture overlaps the northwest rupture extent of the

1981 Dawu earthquake The 1981 Dawu earthquake occurred on , in Sichuan, China. Registering a surface-wave magnitude of 6.8, the earthquake killed about 150 people and injured roughly 300 more. It caused comprehensive damage within close range of its epicenter. Backg ...

. A maximum coseismic slip of 3.3 meters was measured near the village of Dazhai, while the average slip across the rupture was 3.0 meters.

Coulomb stress transfer Coulomb stress transfer is a Seismology, seismic-related geology, geological process of Stress (mechanics), stress changes to surrounding material caused by local discrete deformation events. Using mapped displacements of the Earth's surface during ...

may have increased strain on the segment north of the 1923 earthquake rupture, causing it to fail during the 1973 earthquake.

Damage

In Luhuo county, the city's

defensive wall A defensive wall is a fortification usually used to protect a city, town or other settlement from potential aggressors. The walls can range from simple palisades or earthworks to extensive military fortifications such as curtain walls with t ...

s toppled to the ground. Many homes, official buildings, and places of worship were totally destroyed.

Avalanche An avalanche is a rapid flow of snow down a Grade (slope), slope, such as a hill or mountain. Avalanches can be triggered spontaneously, by factors such as increased precipitation or snowpack weakening, or by external means such as humans, othe ...

s and

landslide Landslides, also known as landslips, rockslips or rockslides, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslides ...

s occurred on the mountains.

Fissure A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word , which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes. Ground fissure A ...

s measuring up to 2 meters across appeared in the ground. The death toll is in excess of 3,000 people. Two villages in Dawu county were razed to the ground; none left standing. An estimated 500 people were killed in the county. Several residents died in Qianning while many homes and schools were lost. At

Kangding Kangding ( zh, c=康定), also known as Dartsedo (), is a county-level city and the seat of Garzê Tibetan Autonomous Prefecture in Sichuan province of Southwest China. Kangding is on the bank of the Dadu River and has been considered the his ...

, at least 1,300 people died during a severe

rockfall A rockfall or rock-fallWhittow, John (1984). ''Dictionary of Physical Geography''. London: Penguin, 1984. . is a quantity of Rock (geology), rock that has fallen freely from a cliff face. The term is also used for collapse of rock from roof or wa ...

. Many temples suffered partial collapses whils poorly-constructed homes were destroyed. Damage to homes was also reported in

Garzê Town Kardze or Garzê (), called Ganzi in Chinese (), is a town and county seat in Kardze County, Kardze Tibetan Autonomous Prefecture in western Sichuan Province, China. Despite Kardze Prefecture being named after the town, the prefecture capital ...

Xinlong Xinlong or Nyagrong County ( zh, s=新龙县; ) is a county in the west of Sichuan Province, China. It is under the administration of the Garzê Tibetan Autonomous Prefecture. Xinlong County is part of historical region of Nyarong. Jazi (Nyarong ...

and

Litang Litang may refer to: * Litang or Lithang County (理塘县) in Sichuan/Kham, site of the Lithang Monastery *Chiefdom of Lithang (1719–1906), a Tibetan polity *Litang, Guangxi (黎塘镇), town in Binyang County *Li Tang (hall of worship) T ...

References

External links

* {{Earthquakes in China Earthquakes in Sichuan 1923 earthquakes 1923 in China Garzê Tibetan Autonomous Prefecture March 1923 1923 disasters in China 1923 disasters in Asia

Tectonic setting

Earthquake

Damage

See also

References

External links