Hypocenter Relocation along the Sunda Arc in Indonesia, Using a 3D Seismic‐Velocity Model

Structural Controls on Rupture Extent of Recent Sumatran Fault Zone Earthquakes, Indonesia

“…Between these two events, most seismicity (blue circles and focal mechanisms) was associated with the Sumatran fault segments (drawn as multicolor lines), including the January 2013 M w 6.1 earthquake in Aceh segment (Ito et al, 2016) and the July 2013 M w 6.1 Tanah Gayo earthquake~30 km from the nearest segment of the Sumatran fault (Daryono & Tohari 2016;Gunawan et al, 2018). Historical events are from Pesicek et al (2010) and Nugraha et al (2018). Aftershock distributions (M L 1-4) are for the period of 14 December 2016 to 15 January 2017 (Muzli et al, 2018).…”

“…Red stars and colored contours represent epicenter location and areas of ≥1m coseismic slip for three great earthquakes (M w > 8) on the Sunda megathrust (Chlieh et al, 2007;Konca et al, 2007;Tsang et al, 2016). The other colored dots are relocated shallow (nonmegathrust) earthquakes during the periods 1960-2009(Pesicek et al, 2010 and 2009(Nugraha et al, 2018. Plate convergence rates in inset map are from DeMets et al (2010).…”

“…To better assess seismic hazard potential of earthquakes in mainland Sumatra, published studies have focused on paleoearthquakes (Bellier et al, 1997), epicenter relocations (Hurukawa et al, 2014;Newcomb & McCann, 1987;Nugraha et al, 2018;Pesicek et al, 2010), aftershock distributions (Muzli et al, 2018;Widiwijayanti et al, 1996), field observations of surface ruptures (Daryono et al, 2012;Daryono & Tohari, 2016;Untung et al, 1985), deterministic and probabilistic hazard assessments (Natawidjaja & Triyoso, 2007), active fault mapping (Fernandez-Blanco et al, 2016;Muksin et al, 2019;Natawidjaja et al, 2017;Sieh & Natawidjaja, 2000;Weller et al, 2012), fault slip rates (Bellier & Sebrier, 1995;Bradley et al, 2017;Genrich et al, 2000;Ito et al, 2012;Natawidjaja et al, 2017;Prawirodirdjo et al, 2000;Tong et al, 2018), in situ stress analysis (Sahara et al, 2018), source characteristics of ruptures (Duquesnoy et al, 1996;Gunawan et al, 2018;Ito et al, 2016;Prawirodirdjo et al, 2000;Reid, 1913), and postseisimic processes (Gunawan et al, 2019). However, none of these studies used well-constrained near-field geodetic data to address the seismogenic depth and spatial distribution of coseismic slip, or to study the nature of the tectonic features that control earthquake rupture sizes along the SFZ.…”

Implications for megathrust earthquakes and tsunamis from seismic gaps south of Java Indonesia

“…The epicentral shifts of relocated events are in general perpendicular (north–south direction) to the Java Trench (Supplementary Fig. 1 b and c), which may be caused by the stations being mainly distributed to the north on Java 15 , 19 . Similarly, since all seismometers are placed on the surface above the earthquakes, there are also shifts in the vertical direction (Supplementary Fig.…”

Analysis of the destructive earthquakes end of 2017 (Mw 6.9) and early 2018 (Mw 6.1) south of West Java, Indonesia

“…The Indo-Australian plate moves with an approximate convergence velocity of 70 mm/yr [2]. The relocated earthquake catalog from previous studies [3][4][5]shows high seismicity in the area, distribution of the earthquake hypocenter is getting deeper from the trench to West Java. Over the past two decades, there have been two destructive events in the south of Western Java, i.e.…”