A development of double-difference earthquake location program using three-dimensional velocity model and its application to the 2013 Ruisui, Taiwan, earthquake sequence

• Main Authors: Shu-Heng Lin, 林樞衡
• Other Authors: Yih-Min Wu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/33323854158021536661

碩士 === 國立臺灣大學 === 地質科學研究所 === 102 === Double-difference algorithm is one of the methods used in earthquake relocation. The widely used double-difference relocation program is hypoDD (Waldhauser and Ellsworth, 2000; Waldhauser, 2001). It only supports using layered velocity model in the relocation process. To improve the relocation result by using higher resolution velocity model, we developed a double-difference earthquake relocation program using three-dimensional velocity model (3D-DD). Moreover, we also joint single-event relocation method with double-difference location algorithm during the inversion procedure, in order to prevent losing the relocation results when double-difference location algorithm is only used. The performance of the program was tested by a series of synthetic data tests, and the location error of 3D-DD is smaller than the error of hypoDD and a three-dimensional single event earthquake relocation program. We also apply our method on the relocation of Ruisui, Taiwan, earthquake sequence occurred on October 31st, 2013. The relocated hypocentral distribution is much more concentrated and linear. The location error and residual also became smaller after relocated by this method. By relocated hypocenters and velocity structure of Taiwan area, the cause of Ruisui earthquake may be the tectonic activity of the Luzon forearc crust.