The NextM~6 Event in Parkfield Implied by a Physical Model Linking Interseismic, Coseismic, and Postseismic Phase

Abstract

Determination of the constitutive frictional parameters is crucial for describing the dynamic behaviors of natural faults. In this study, we explore the along‐strike variation in fault friction along the San Andreas Fault in Parkfield, where characteristic M6 earthquakes occur nearly every 25 years. Using displacement data measured over decades encompassing the interseismic, coseismic, and postseismic phase of the 2004 M6 event, which involve inherent fault rheological responses to tectonic loading, we construct a physical model based on the rate‐dependent friction law to describe the fault slip and stress evolution. Our modeled friction rate parameter is consistent with available laboratory measurements using fault cores collected from the San Andreas Fault Observatory at Depth. Based on the physical model linking interseismic, coseismic, and postseismic phase, we predict that the 25‐year slip deficit following the 2004 M6 earthquake will predominantly accumulate in the area to the south of the 2004 event hypocenter, with an energy equivalent to a M6.0 event. Together with the slip deficit accumulated over the 25 years prior to the 2004 event that was unreleased by this event, the total slip deficit amounts to a moment magnitude of M6.35 ± 0.11, suggesting the upper limit of the seismic release level until 2029. The proposed model (1) involves only two free quantities (the friction rate parameter and velocity coefficient used to determine the effective normal stress); (2) is well constrained by available interseismic, coseismic, and postseismic displacement data; and (3) highlights along‐strike variations in the fault friction.

Bayesian Inference of Fault Slip and Coupling Along the Tuosuo Lake Segment of the Kunlun Fault, China

“…Displacement along continental‐scale strike‐slip faults has been important in the formation of the Tibetan Plateau and in the modulation of contemporary crustal responses to the India‐Eurasia collision (e.g., England & Houseman, 1986; Molnar & Tapponnier, 1975). Variations in fault slip and coupling constitute measures of fault friction, geometric control, rupture segmentation, and seismic hazard (e.g., Avouac, 2015; Barbot et al., 2012; Diao et al., 2019; Lin et al., 2006; Nie & Barbot, 2021; L. Wang, 2018).…”

The 8 January 2022, Menyuan Earthquake in Qinghai, China: A Representative Event in the Qilian-Haiyuan Fault Zone Observed Using Sentinel-1 SAR Images

“…This phenomenon is widespread in other regions that have been thoroughly investigated, including the 2004 M6 Parkfield earthquake [4] and 2011 M9 Tohoku-Oki earthquake [3]. The frictional properties of the fault plane can also be constrained by interseismic fault locking, coseismic slip distribution, and post-seismic fault slip rate [86]. Yang et al [5] used numerical simulations to confirm that interseismic locking places optimal constraints on the seismic rupture process.…”

Excitation of San Andreas tremors by thermal instabilities below the seismogenic zone

“…We use a = 10 −2 and a − b = 4 × 10 −3 , compatible with the postseismic geodetic measurements following the 2004 Mw 6.0 event (41). We drive the slider with a background rate of V L = 31 mm/year, i.e., V L = 1 nm/s, compatible with the long-term deep creeping rate of the San Andreas fault (42). For the reference temperature, we use the steady-state temperature of the evolution law (Eq.…”