PLD method for retrieving apparent source time function and its application to the 2005 Kashmir MW7.6 earthquake
提取视震源时间函数的PLD方法及其对2005年克什米尔MW7.6地震的应用

The PLD method for retrieval of apparent source time function (ASTF) is improved by reconstructing the criteria function to be used for determination of the effective duration time of the ASTF. Using the synthetic and observed data, the feasibility and stability of the improved PLD method are verified. By applying the PLD method to 1887 waveform recordings of the 2005 Kashmir MW7.6 earthquake and its 11 aftershocks, the ASTFs of the main shock are obtained at 84 stations. By averaging the ASTFs from the P waves, S waves, Rayleigh waves and Love waves from different stations, the average ASTFs of the main shock are constructed. The analysis of the ASTFs indicates that the duration time of the 2005 Kashmir MW7.6 earthquake is about 25 s, and it is a quickly-starting earthquake. In general feature, the STF appears to be like a STF of a circular source model, however, some details of the ASTFs suggest that the rupture at the beginning was unilateral extending toward NW direction.