The 2003 Dayao earthquake occurred on July 21, at 23:16:33 CST. The epicenter of the
moment magnitude 5.9 earthquake was in
Dayao County
Dayao County (; Chuxiong Yi script: , IPA：) is a county of north-central Yunnan province, People's Republic of China, under the administration of Chuxiong Yi Autonomous Prefecture.
Administrative divisions
Dayao County has 8 towns, 3 townships ...
in the mountainous area of central
Yunnan
Yunnan , () is a landlocked Provinces of China, province in Southwest China, the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is ...
, China. At least 19 people were killed, 644 were injured,
and 8,406 families became homeless. The quake also caused $75 million
USD in damage.
Tectonic setting
Yunnan is located at the southeastern edge of the
Tibetan Plateau
The Tibetan Plateau (, also known as the Qinghai–Tibet Plateau or the Qing–Zang Plateau () or as the Himalayan Plateau in India, is a vast elevated plateau located at the intersection of Central, South and East Asia covering most of the Ti ...
, where the
Indian Plate
The Indian Plate (or India Plate) is 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 , began mov ...
is
colliding
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 fo ...
north–northeast into the
Eurasian Plate
The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...
(Asia). The continental deformation is accommodated by major faults in the area, mostly of
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 ...
movement. The Indian Plate pushes into Asia, uplifting the Tibetan Plateau and causes it rotate clockwise, along the
Xianshuihe fault system
The Xianshuihe fault system is a major active sinistral (left-lateral) strike-slip fault zone in southwestern China, at the eastern edge of the Tibetan Plateau. It has been responsible for many major earthquakes, and is one of the most seismically ...
. This deformation spreads into Yunnan, where active strike-slip faulting occurs.
Earthquake
The earthquake measured 6.1 on the surface-wave magnitude scale. It was the first of two earthquakes in the same area that year. In October, an 6.2 ( 5.6) earthquake struck nearby, killing three people.
The July earthquake occurred as a result of shallow strike-slip faulting.
Coulomb stress transfer Coulomb stress transfer is a seismic-related geological process of stress changes to surrounding material caused by local discrete deformation events. Using mapped displacements of the Earth's surface during earthquakes, the computed Coulomb stress ...
from the July quake increased the chance of failure on nearby faults which triggered the October quake.
Impact
The quake occurred when most victims were asleep. In the village of Ganghe, at least 11 people were killed due to collapsing homes made of mud. An aftershock on July 23 caused additional collapses and injured 51 people.
In Songziyuan village, many homes were destroyed. Large
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 opened in roads and
landslide
Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated grade (slope), slope failures, mudflows, and debris flows. Landslides occur in a variety of ...
s blocked passing vehicles. At least one person died in the village. A total of 264,474 houses collapsed, leaving many homeless.
See also
*
List of earthquakes in 2003
This is a list of earthquakes in 2003. Only earthquakes of magnitude 6 or above are included, unless they result in damage and/or casualties, or are notable for some other reason. All dates are listed according to UTC (Coordinated Universal Tim ...
*
List of earthquakes in China
This is a List of earthquakes in China, part of the series of lists of disasters 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. Earthq ...
*
List of earthquakes in Yunnan
This is a list of earthquakes that have occurred in or have affected Yunnan Province in China.
Major earthquakes (≥Magnitude 7.0)
Major earthquakes (Magnitude 6.0–6.9)
Moderately large earthquakes (≤Magnitude 5.9)
See also
* ...
References
External links
*
{{Earthquakes in China
2003 earthquakes
Earthquakes in Yunnan
Geography of Chuxiong Yi Autonomous Prefecture
2003 disasters in China
2003 in China