Source mechanism and triggered large aftershocks of the Mw 6.5 Ambon, Indonesia earthquake

The Seismicity of Indonesia and Tectonic Implications

“…Notable strike-slip faults on Seram include the sinistral Kawa and Bobol faults (Figure 16; Patria & Hall, 2017;Watkinson & Hall, 2017). Few strike-slip focal mechanisms ≥M 5.0 are evident along these faults, though geomorphic expressions interpreted by Watkinson and Hall (2017) indicate the Kawa fault is capable of ground-rupturing events, as are other faults on the island, such as the recently reactivated fault responsible for the destructive 2019 M w 6.5 Ambon earthquake (Figure 16b; Table 3; Sahara et al, 2021). Mixed strike-slip and reverse mechanisms ≥M 5.0 between Seram island and the western Sorong fault suggest the transfer of sinistral shear between them is very complex.…”

“…seismicity, tectonics, and associated hazards. Numerous recent studies have been conducted to better understand Indonesian seismicity and tectonics, identifying and imaging sources of seismicity such as subduction zones and crustal faults (Bock et al, 2003;Bradley et al, 2017;Charlton, 2000;Cipta et al, 2016;Fan & Zhao, 2018;Hall, 2012Hall, , 2018Hall & Spakman, 2015;Hinschberger et al, 2005;Irsyam et al, 2020;Koulali et al, 2016;Sieh & Natawidjaja, 2000;Omang et al, 2016;Patria & Putra, 2020;Sahara et al, 2021;Socquet et al, 2006;Spakman & Hall, 2010;Supendi et al, 2018;Watkinson & Hall, 2017;Watkinson et al, 2011;Widiyantoro et al, 2011aWidiyantoro et al, , 2011b. However, no recent study provides a comprehensive summary of seismicity for all of Indonesia.…”

“…Elevated seismic activity, particularly in the past two decades, has produced five great magnitude events, the largest being the December 26, 2004 M w 9.1 Great Sumatra‐Andaman earthquake and tsunami (Lay et al., 2005), and several other damaging events motivating a need to further understand Indonesian seismicity, tectonics, and associated hazards. Numerous recent studies have been conducted to better understand Indonesian seismicity and tectonics, identifying and imaging sources of seismicity such as subduction zones and crustal faults (Bock et al., 2003; Bradley et al., 2017; Charlton, 2000; Cipta et al., 2016; Fan & Zhao, 2018; Hall, 2012, 2018; Hall & Spakman, 2015; Hinschberger et al., 2005; Irsyam et al., 2020; Koulali et al., 2016; Sieh & Natawidjaja, 2000; Omang et al., 2016; Patria & Putra, 2020; Sahara et al., 2021; Socquet et al., 2006; Spakman & Hall, 2010; Supendi et al., 2018; Watkinson & Hall, 2017; Watkinson et al., 2011; Widiyantoro et al., 2011a, 2011b). However, no recent study provides a comprehensive summary of seismicity for all of Indonesia.…”

Focal Mechanism Inversion on the Aftershock Sequence of the 25 October, 2010 Mw 7.8 Mentawai Earthquake: A Preliminary Result

“…The precise hypocenter location and fault plane solutions of the aftershock sequence can provide critical information about the fault geometry [12,13] while identifying the possibility of active faults' existence near the main rupture zone [14]. An understanding of these two aspects then becomes very important for seismic hazard assessment in the region of active convergence plate margin.…”

“…The red shape indicates the coseismic slip ≥ 1 m of the 2010 Mentawai earthquake[2]. Black dashed lines are the depth contour of the slab from the Slab 1.0 model[11].The precise hypocenter location and fault plane solutions of the aftershock sequence can provide critical information about the fault geometry[12,13] while identifying the possibility of active faults' existence near the main rupture zone[14]. An understanding of these two aspects then becomes very…”