This study comprehensively investigates the source mechanisms associated with the mainshock and aftershocks of the Mw = 6.3 Yogyakarta earthquake which occurred on May 27, 2006. The process involved using moment tensor inversion to determine the fault plane parameters and joint inversion which were further applied to understand the spatial and temporal slip distributions during the earthquake. Moreover, coseismal slip distribution was overlaid with the relocated aftershock distribution to determine the stress field variations around the tectonic area. Meanwhile, the moment tensor inversion made use of near-field data and its Green’s function was calculated using the extended reflectivity method while the joint inversion used near-field and teleseismic body wave data which were computed using the Kikuchi and Kanamori methods. These data were filtered through a trial-and-error method using a bandpass filter with frequency pairs and velocity models from several previous studies. Furthermore, the Akaike Bayesian Information Criterion (ABIC) method was applied to obtain more stable inversion results and different fault types were discovered. Strike–slip and dip-normal were recorded for the mainshock and similar types were recorded for the 8th aftershock while the 9th and 16th June were strike slips. However, the fault slip distribution from the joint inversion showed two asperities. The maximum slip was 0.78 m with the first asperity observed at 10 km south/north of the mainshock hypocenter. The source parameters discovered include total seismic moment M0 = 0.4311E + 19 (Nm) or Mw = 6.4 with a depth of 12 km and a duration of 28 s. The slip distribution overlaid with the aftershock distribution showed the tendency of the aftershock to occur around the asperities zone while a normal oblique focus mechanism was found using the joint inversion.

中文翻译：

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2006年日惹M6.3地震主震和余震数据的波形反演

本研究全面调查了与2006年5月27日发生的日惹6.3级地震主震和余震有关的震源机制。该过程涉及使用矩张量反演来确定断层面参数和联合反演，从而进一步理解了这一点。地震期间的时空滑移分布。此外，同震滑动分布与重新定位的余震分布重叠，以确定构造区域周围的应力场变化。同时，矩张量反演利用近场数据，格林函数使用扩展反射率法计算，联合反演使用近场和远震体波数据，这些数据是用菊池法和金森法计算的。这些数据通过试错法使用带通滤波器进行滤除，该带通滤波器具有来自先前几项研究的频率对和速度模型。此外，运用赤池贝叶斯信息准则（ABIC）方法获得更稳定的反演结果，并发现了不同的断层类型。记录了主震的走滑和倾角法线，而在第8次余震中记录了类似类型，而6月9日和16日则是走滑。然而，来自联合反演的断层滑动分布显示出两个粗糙点。最大滑移为0.78 m，在主震震源南北10 km处观察到第一处凹凸不平。发现的震源参数包括总地震矩M0 = 0.4311E + 19（Nm）或Mw = 6.4，深度为12 km，持续时间为28 s。