THE MACROSEISMIC
MANIFESTATIONS OF THE 2008 WENCHUAN DISASTROUS EARTHQUAKE (MS = 8.0)
ACCORDING TO THE STUDY
OF SURFACE SEISMODISLOCATIONS
Jiao Liu1, E.A. Rogozhin2
1 Lomonosov Moscow State University, Moscow,
Russia
2 Schmidt Institute of
Physics of the Earth, Russian Academy
of Sciences, Moscow, Russia
Abstract. On May 12, 2008, in Wenchuan, in the Sichuan province
of China, a large
intraplate MS = 8.0
earthquake occurred along the Longmen Shan thrust fault zone. The hypocenter
depth is
14 km. The mainshock of the Wenchuan earthquake ruptured the ground surface and
formed primary seismic faults system: Beichuan–Yingxiu Fault up to 240 km long; Guanxian–Anxian
Fault about
70 km
long and Xiaoyudong Fault 7 km
long. On the map of the
general seismic zoning in China in 2001, the epicentral region of the Wenchuan
earthquake fell into the zone with an expected intensity of 7 degree. The
maximum measured vertical and dextral displacements along the faults are up to
10 m and 4.8 m, respectively.
Moreover, the earthquake generated tens thousands of landslides and rock
avalanches. Much of the destruction of infrastructure and human casualties are
mainly associated with the extensive development of activation of geological
processes. The seismic intensity of surface shaking was anomaly low even also
to the seismic faults system. The collected data on the distribution of primary
and secondary effects of earthquakes has helped to delineate the zones 8, 9 and
10 quakes. Guidance on the assessment of the intensity of the shock was the
scale of EEE (Earthquake environmental effects) developed in one project INQUA
(2004–2016). In general, the zone of intense surface deformation forms a long,
narrow oval, elongated in a north-east direction, corresponding with the strike
system seismic faults.
Keywords:
Wenchuan
earthquake, rupture, faults, disaster, macroseismic effect, intensity,
isoseismic line, environmental effects.
LIU JIAO –
PhD student, Lomonosov Moscow State University. Moscow, Russia. Tel.: +7 (968) 353-89-11.
E-mail: liujiao8926@mail.ru
POGOZHIN E.A. – dr in geol.-min. sci., professor, deputy
director, Schmidt Institute of Physics of the Earth, Russian Academy of
Sciences. Moscow,
Russia. Tel.: +7 (499) 254-87-15. E-mail: eurog@ifz.ru