A Study on the Characteristics of the Yutian,Xinjiang MS7.3 Earthquake,February 12,2014

The February 12,2014,MS7.3,earthquake in Yutian,Xinjiang,China,occurred as a result of shallow strike-slip faulting in the tectonically complex region of the northern Tibetan Plateau,with a depth of 17 km.This earthquake occurred several hundred kilometers north of the convergent India-Eurasia plate boundary.The epicenter location of the Yutian earthquake,36.1° N,82.5° E,is 110 km north of Yutian County,Hotan Prefecture.A large number of aftershocks from ML2.0 to ML3.0 occurred until 12:00oclock,February 23,2014 and the largest aftershock,MS5.7,occurred at 17:24 p.m.,February 12,2014.The b and h value of Yutian sequence are 0.70 and 1.29,respectively.The waiting time method reveals that the strong aftershocks above ML4.5comply with a linear relationship,which is consistent with the characteristics of a mainshock-aftershock sequence.Furthermore,we calculate the source parameters and analyze the rupture process based on the empirical relationships for the Yutian earthquake,and the results indicate a frictional undershoot behavior in the dynamic source process of the Yutian earthquake,which is also in agreement with the lower and similar b values compared with the 2008 MS7.3 Yutian earthquake and the 2012 MS6.2 Yutian earthquake.