Surface Creep Rate and Moment Accumulation Rate Along the Aceh Segment of the Sumatran Fault From L‐band ALOS‐1/PALSAR‐1 Observations

Abstract

We analyzed the interferometric synthetic aperture radar data from the ALOS‐1/PALSAR‐1 satellite to image the interseismic deformation along the Sumatran fault. The interferometric synthetic aperture radar time series analysis reveals up to ~20 mm/year of aseismic creep on the Aceh segment along the Northern Sumatran fault. This is a large fraction of the total slip rate across this fault. The spatial extent of the aseismic creep extends for ~100 km. The along‐strike variation of the aseismic creep has an inverse “U” shape. An analysis of the moment accumulation rate shows that the central part of the creeping section accumulates moment at approximately 50% of the rate of the surrounding locked segments. An initial analysis of temporal variations suggests that the creep rate may be decelerating with time, suggesting that the creep rate is adjusting to a stress perturbation from nearby seismic activity. Our study has implications to the earthquake hazard along the northern Sumatran fault.

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

“…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.…”

Present-Day Deformation of the Gyaring Co Fault Zone, Central Qinghai–Tibet Plateau, Determined Using Synthetic Aperture Radar Interferometry

“…To compare the results of the InSAR and GPS deformation rates, we selected a cross-section of aa', and extracted the InSAR deformation rate within 5 km of the profile line and the velocity results of the GPS stations within 100 km, respectively ( Figure 6). The GPS measurements used in this study were provided by Zheng et al [18]. The GPS data were collected through campaign and continuous modes, with surveying times in 1998,1999,2001,2004,2007,2009, 2011, 2013, and 2015.…”

“…At present, the application of InSAR technology in co-seismic deformation has become quite mature (e.g., [12]) with more applications regarding deformation after strong earthquakes (e.g., [13]). During recent years, with the increase in the number of SAR satellites and the shortening of the repeat cycle, along with the development of InSAR data processing, InSAR technology has been successfully applied to the extraction of slow deformation during a period of seismic activity, such as for the Altyn Tagh (e.g., [14]), San Andreas (e.g., [15]), Anatolian (e.g., [16]), Haiyuan (e.g., [17]), Sumatran (e.g., [18]), and Xianshuihe faults (e.g., [19]). These studies demonstrate that InSAR technology can monitor the surface deformation of a fault zone with millimeter precision, providing important evidence for the study of fault kinematics and regional tectonic evolution.…”

The Relationship Between Seismic and Aseismic Slip on the Philippine Fault on Leyte Island: Bayesian Modeling of Fault Slip and Geothermal Subsidence

“…The earliest InSAR observations of the seismic cycle revolutionized our ability to explore fault and crustal mechanics (e.g., Deng, 1998; Massonnet et al, 1993; Peltzer et al, 2001; Price & Sandwell, 1998; Wright et al, 2001). Continuous monitoring through interseismic periods has further enabled us to delineate aseismic slip on remote and less well instrumented faults (e.g., Cavalié et al, 2008; Cetin et al, 2014; Jolivet et al, 2013; Fattahi & Amelung, 2016; Pousse Beltran et al, 2016; Thomas, Avouac, Champenois, et al, 2014; Tong et al, 2018). This allows us to discover and explore potential earthquake sources that might not be well known, like on faults sometimes referred to as “creeping faults” (e.g., Jolivet, Simons, et al, 2015).…”