1932 Changma earthquake
UTC time | 1932-12-25 02:04:30 |
---|---|
ISC event | 906530 |
USGS-ANSS | ComCat |
Local date | December 25, 1932 |
Local time | 10:04:30 |
Magnitude | 7.6 Ms |
Epicenter | 39°42′N 96°42′E / 39.7°N 96.7°E[1] |
Areas affected | Republic of China |
Max. intensity | MMI X (Extreme)[1] |
Casualties | 275–70,000 dead |
The 1932 Changma earthquake occurred at 10:04:27 local time (02:04:07
Tectonic setting
The earthquake was located close to the northern margin of the Tibetan Plateau. This area of thickened crust is a result of the ongoing collision of the Indo-Australian Plate with the Eurasian Plate. The way in which this zone accommodates the collision remains unclear with two end-member models being proposed. The first regards the crust as being made up of a mosaic of strong blocks separated by weak fault zones, the microplate model. The second regards the deformation as being continuous within the mid to lower crust, the continuum model. The change in width of the deformed zone along the collisional belt, with the narrow zone of western Tibet compared to the main part of the Tibetan Plateau, is explained as either lateral escape to the east along the Altyn Tagh and Karakorum faults in the microplate model or as the effect of the rigid Tarim Basin block causing heterogeneous deformation within a generally weaker lithosphere in the continuum model.[4] At its northern end, the Altyn Tagh fault progressively loses displacement by its interaction with a series of WNW–ESE trending structures, mostly with components of reverse displacement and sinistral (left lateral) strike-slip. The Changma fault is one of those structures.[5]
Damage
The region stricken by this earthquake included the entire
Characteristics
A surface rupture of about 116 km was identified after the earthquake, including five separate fault segments,[1] the largest rupture observed for a reverse-slip event in Asia in the twentieth century.[6] Four of the segments that ruptured were reverse faults, the fifth was a strike-slip fault. Vertical offsets of more than a metre were observed on most of the segments, with a maximum of 5 m.[7]
Seismic hazard implications
The 1932 Changma earthquake shows that apparently separate mapped intracontinental reverse faults may rupture simultaneously in an earthquake. Estimates of the seismic hazard in an area based on the rupture of single reverse faults may lead to a major underestimate of the magnitudes of the largest possible earthquake.[7]
See also
References
- ^ doi:10.7289/V5TD9V7K.
- ScienceNet.cn. Retrieved 26 September 2021.
- ^ Wang Fugui (16 September 2021). "中国历史上伤亡惨重的十大地震 [Ten earthquakes with heavy casualties in Chinese history]". sunnews.cn. Retrieved 26 September 2021.
- doi:10.1029/2002JB002080. Archived from the original(PDF) on 18 July 2010. Retrieved 3 November 2010.
- .
- . Retrieved 18 November 2010.
- ^ hdl:2060/19980029715. Retrieved 18 November 2010.
External links
- The International Seismological Centre has a bibliography and/or authoritative data for this event.