Relative Structural Complexity of Plate‐Boundary Fault Systems Controls Incremental Slip‐Rate Behavior of Major Strike‐Slip Faults

Abstract

Understanding the manner in which major plate-boundary-scale faults accommodate slip is of critical importance for a wide range of issues in the Earth sciences, including the geodynamics of relative plate motions, the mechanics of storage of elastic strain energy on faults and the release of that energy during earthquakes, the steadiness and predictability of fault slip through time, and the use of geological slip-rate data in seismic hazard assessment. Previous analyses of major plate-boundary strike-slip faults have revealed a wide range of behaviors, from relatively constant slip rates spanning a range of time intervals on some faults (

Comparison of geodetic slip-deficit and geologic fault slip rates reveals that variability of elastic strain accumulation and release rates on strike-slip faults is controlled by the relative structural complexity of plate-boundary fault systems

“…In this study, we use the recently developed Coefficient of Complexity (CoCo) method (Gauriau and Dolan, 2021), which quantifies the relative structural complexity of the fault network surrounding a fault of interest by integrating the density and displacement rates of the faults in the plate-boundary network at a specific radius (here, 100 km) around the site of interest. The method is illustrated in Figure 1.…”

“…In our original formulation of the CoCo metric (Gauriau and Dolan, 2021), we categorized faults as either lowor high-CoCo. To determine the CoCo metric for each fault study site, we apply a system in which we recognize that the degree of structural complexity surrounding a fault is a continuum, with no hard boundary between high-and low-CoCo faults.…”

“…Slight differences between the datasets could be attributable to shortlived periods of higher-than-average strain accumulation during the post-seismic period. The geologic rates used as inputs into the analysis of Meade et al (2013) span a huge range of displacement and time scales, from as small as ~13 m to as large as ~600 m, and as short as 2 ky to as long as 160 ky. We recently presented results that demonstrate that, for faults that lie within complex plate-boundary fault networks, geologic slip rates vary depending on the displacement scale over which the slip rate is estimated; on the other hand, structurally isolated faults that accommodate most of the relative motion within simple plate boundaries exhibit steadier slip rates (Gauriau and Dolan, 2021). These observations lead us to explore the possibility that differences between geodetic slip-deficit rates and geologic slip rates might also be sensitive to the relative complexity of the surrounding fault network.…”

Variations of the seismic b-value along the Dead Sea transform

“…Thus, although the b-value is expected to vary between regions according to the faulting style , such interpretations between different faults of different regions should be made carefully. Here, we compare our results, regarding the DST, with three other major continental transform fault systems (e.g., Gauriau and Dolan, 2021).…”

Contribution of Viscoelastic Stress to the Synchronization of Earthquake Cycles on Oceanic Transform Faults

“…The recurrence pattern of earthquakes is affected by the non‐linear mechanics of fault friction (Leeman et al., 2016; Ma & He, 2001; Mele Veedu et al., 2020; C. Mei et al., 2021), the complex structural fabric of the fault zone (Dolan et al., 2016; Nie & Barbot, 2022; Wesnousky, 1988), and the interactions with other faults through static and remote triggering (Freed & Lin, 2001; Gauriau & Dolan, 2021; Gomberg & Johnson, 2005; King et al., 1994). Temporal clustering is a recurrent observation in paleoseismic records, for example, on the San Andreas Fault (Weldon et al., 2004), the Lazio‐Abruzzo fault system in Central Italy (Benedetti et al., 2013), and the Cascadia subduction zone (Goldfinger et al., 2013).…”