Rapid Identification Method of Earthquake Intensity Influence Field in Divided-Period After Earthquake

  Objectives  After the devastating earthquake, rapid determination of earthquake intensity influence field in post-earthquake is the key on loss estimation of earthquake disaster and emergency rescue.It is necessary to explore how to obtain the influence field with multi-source data on different periods. Accurate earthquake influence field is an important basis for emergency commands and decisions.

  Methods  We discussed on determine and correct the earthquake intensity influence field in three periods: After obtaining three elements of earthquake, acquiring strong motion instrument intensity and earthquake field investigation data. After obtaining three elements of the earthquake, the preliminary results on earthquake intensity influence field using earthquake intensity attenuation relationship of different regions in Chinese mainland.Then we modified the preliminary results on earthquake intensity influence filed using the spatial interpolation after obtained the strong motion intensity record. At last, we modified the earthquake intensity influence filed jointly using strong motion instrument intensity and field investigation data. Then we could provide a scientific and accurate theoretical method and implementation technology of earthquake influence field identification, within 12 hours after the destructive large earthquake.

  Results  Taking the 2013 Lushan M7.0 earthquake in Sichuan Province as an example, we calculate and revise the earthquake intensity influence field in divided-periods. On the first period, the earthquake influence field is generated rapidly according to the three earthquake elements and the attenuation relationship. On the second period, by using strong seismic data and interpolation method, earthquake high intensity is given accurately. On the third period, integrate multi-source data and the calculated results have a good consistency with the actual earthquake intensity.

  Conclusions  The high intensity region can be accurately interpreted by this method. At the same time, the direction of seismic intensity attenuation and the intensity of the instrument intensity can jointly constrain the trend and boundary of the low-intensity area. Furthermore, a more accurate influence field of intensity is given to provide technical support for the early earthquake emergency work.