Study on bias correction of ShakeMaps based on limited acceleration records

We investigated bias correction method of ShakeMaps based on limited acceleration records for the 10 April 2011 Luhuo, Sichuan, earthquake (MS5.3) and the 11 August 2011 Jiashi, Xinjiang, earthquake (MS5.8). By analyzing residuals between the observed data and calculated values, we proposed a method of logarithmic deviation correction for theoretical estimates in regions lacking seismic observations. We also compared both logarithmic residuals and vibration distribution between circle attenuation model and ellipse attenuation model. Research and analysis show that rules of plusmn;3 times standard deviation of local ground motion attenuation relations can remove some abnormal station data, such as the abnormal data from Luhuo Diban station for Luhuo earthquake due to near-field high-frequency acceleration pulses. During rapid report of ground motion intensity, the method of logarithmic deviation correction is suitable for systematic error correction of theoretical estimates of ground motion parameters. Circle attenuation model can only control the degree of vibration, but can not control its distribution. The information of focal mechanism, rupture process, local geological structure and distribution of aftershocks of an earthquake can help modify the distribution of ShakeMaps.