  | |
| Local date | June 28, 1626 (1626-06-28) |
|---|---|
| Magnitude | Ms 7.0[1] |
| Epicenter | 39°24′N114°12′E / 39.4°N 114.2°E /39.4; 114.2[2] |
| Areas affected | Qing dynasty |
| Max. intensity | CSIS IX |
| Casualties | >5,200 dead |
The1626 Lingqiu earthquake had an epicentre inLingqiu County,Shanxi Province during theMing dynasty. The estimated surface wave magnitude (Ms ) 7.0 earthquake caused many buildings to collapse. Over 5,200 people were killed.
The Shanxi Rift System is a seismically active intra-continental rift zone inNorth China. Since 231 BC, eight Ms 7.0 earthquakes have occurred along therift system. The1303 Hongdong,1556 Shanxi, and1695 Linfen earthquakes were the deadliest associated with the rift, with death tolls of 50,000 to 830,000 respectively.[3]
Bounded to the west by theLüliang Mountains, and the east by theTaihang Mountains, the Shanxi Rift forms the eastern boundary of the Ordos Block; a fragment ofcontinental crust within theEurasian plate. Within the rift featureshalf-grabens. It formed when extension began in theMiocene orPliocene, separating the crust into theOrdos Block from theNorth China Craton. The reason for extension in this part of China is still debated although the most agreed hypothesis is crustal deformation resulting from theIndia-Asia collision involving theIndian and Eurasian plates along theMain Himalayan Thrust in theHimalayas, causing the rotation of crustal blocks in China. Other hypotheses areslab rollback of thePacific plate as itsubducts along theeast coast of Japan, or localised intraplate tectonics.[4]
Dip-slip and strike-slip earthquakes inNorth China are consistent with ongoingcrustal extension along the Shanxi Rift System. The rift extends for 1,200 km, and is up to 60 km wide. The graben is bounded by normal faults on both sides capable of generating earthquakes. Extension along therift zone occur at a slow rate of 0.8 ± 0.3 mm/year, therefore earthquakes occur with long intervals of recurrence. The estimated magnitudes of earthquakes by Chinese researchers previously have possible inaccuracies as they are based on written descriptions and death toll from the earthquakes.[5]
Theearthquake rupture involved two conjugated faults; the Shuijian–Luoshuihe Fault, and the Huashanhe Fault. The Shuijian–Luoshuihe Fault is located west ofLingqiu County, where is strikes in a north-northeast direction. A one-meter-highfault scarp is visible on the surface, corresponding to the 1626 earthquake. Both faults have shallow dipping angles in the east and west direction, and have a normal slip sense.[6] It has an estimated magnitude of Ms 7.0 andChina seismic intensity scale rating of IX (Destructive).[7]
In another study, the earthquake is proposed to have occurred in the Fenwei Graben System along a strike-slip fault. The rupture is estimated at 134.13 km by 26 km, with anepicentre located at39°24′N114°12′E / 39.4°N 114.2°E /39.4; 114.2, and ahypocentredepth of 7.5 km beneath the surface.[8]
At Lingqiu, many homes belonging to officials and civillains were destroyed.Liquefaction events occurred; black water erupted from dry wells. More than 5,200 people died in the county. About 80–90% of government offices, homes, and warehouses collapsed inHunyuan County. Much of thecity walls fell. Additional buildings and structures were left in ruins atYuxian, andLaiyuan. It was felt in the provinces ofShandong,Hebei, andHenan. The shaking was also felt inBeijing.[2][9]