Source Characteristics of the 2019 Mw 6.5 Ambon, Eastern Indonesia, Earthquake Inferred from Seismic and Geodetic Data

TitleSource Characteristics of the 2019 Mw 6.5 Ambon, Eastern Indonesia, Earthquake Inferred from Seismic and Geodetic Data
Publication TypeJournal Article
Year of Publication2021
AuthorsMeilano I, Salman R, Rahmadani S, Shi Q, Susilo S, Lindsey E, Supendi P
JournalSeismological Research Letters
Date Published08/2021
Abstract

The 26 September 2019 Mw 6.5 Ambon earthquake has been the largest instrumentally recorded event to occur in Ambon, the capital city of Maluku Islands, eastern Indonesia, and ruptured a previously unmapped active fault. In this study, we use seismic and geodetic data to investigate the source characteristics of the event. Our results show that the rupture process was complex in both the rupture initiation and slip directions. In addition, the rupture was mostly strike‐slip motion with normal component and pure reverse slip in the north of the inverted fault. Our analysis of campaign and continuous Global Positioning System (GPS) velocity fields estimates that the fault has a 4.9 [4.0, 5.5] mm/yr slip rate with an earthquake recurrence interval of 115 [102, 141] yr. In addition, a comparison of the horizontal strain‐rate tensor derived from GPS velocity fields with historical earthquake data shows that Ambon Island and the nearby regions have a high strain accumulation rate correlated with the distribution of Mw≥6 earthquakes, indicating that the regions are seismically active and possibly will experience more Ambon‐type earthquakes in the future.

 

DOI10.1785/0220210021