| Penulis/Author |
Bondan Galih Dewanto, S.T., M.S. (1); Ramadhan Priadi (2); Prof. Ir. Leni Sophia Heliani, S.T., M.Sc., D.Sc., IPU. (3) ; AL SHIDA NATUL (4); Muhammad Yanis (5); Dr. Indranova Suhendro, S.T., M.Sc. (6); Admiral Musa Julius (7) |
| Abstrak/Abstract |
On February 25, 2022, at around 8:39 a.m. local time, a strong Mw 6.1 earthquake struck the Pasaman Barat Regency of West Sumatra, Indonesia. This earthquake hit at a depth of 12 km and was preceded by an Mw 4.9 foreshock a few minutes earlier. The earthquakes originated on a blind fault and were felt in Singapore and Malaysia, followed by a landslide at Mount Talamau. Using the teleseismic inversion technique, this study was carried out to examine the slip distri-bution and asperities of the earthquake. The GGMPlus satellite gravity data, on the other hand, was used to identify the fault location. The source parameters such as strike, dip, and rake are 136°, 70°, and 174°, respectively, based on the inversion technique applied to the teleseismic data. According to the slip distribution, the earthquake was generated by stress from the Sianok Fault. However, the results of the First Horizontal Derivative (FHD) and Second Vertical Derivative (SVD) from satellite gravity data show that the gravity anomaly is straight, indicating that it represents a new segment of an active fault, the Talamau segment as part of the Sumatra Fault Zone (SFZ), following earthquake location distribution based on seismic activity. Based on data processing, it can be concluded the combination of teleseismic and gravity observation is poten-tially applied for delineating the fault structure, which has caused the 2022 Mw 6.1 Pasaman earthquake. Both methods are very effective related to economical and fast, so the technique can be applied to other locations, especially in developing countries such as Indonesia. |
