Bayesian Estimation of Surface Strain Rates From Global Navigation Satellite System Measurements: Application to the Southwestern United States

Abstract

Imaging and quantifying the present-day lithospheric deformation is crucial to understanding how and where long-term tectonic loading is accommodated. Plate tectonics theory assumes that the relative motion of rigid lithospheric blocks is accommodated on a limited set of localized fault zones, where the lithosphere either deforms elastically during the interseismic period of the seismic cycle, or in a brittle way during the coseismic rupture (Isacks et al., 1968;Le Pichon, 1968;Morgan, 1968). In a simple elastic framework, the surface deformation generated by slip on a dislocation buried in an elastic half-space can be computed (e.g., Okada, 1985), as well as the surface deformation produced by full or partial locking of the buried fault using the "backslip" hypothesis (Savage, 1983). Analyzing the spatial patterns of surface deformation and their temporal variations around active faults can therefore help constraining the behavior of fault systems at each stage of the seismic cycle.

Spatial Variations of Slip and Creep Rates Along the Southern and Central Dead Sea Fault and the Carmel–Gilboa Fault System

“…may reflect a small amount of local deformation within the Sinai plate far from the main faults, although they could also result from a poor resolution or biases in our strain rates calculation (e.g., Pagani et al, 2021). Some discrepancies between the two approaches can be found along the DSF and in Jordan, east to the DSF.…”

“…The residuals within the stable Sinai plate (i.e., at distance greater than 30 km from the main faults) are found to be between 8 × 10 −9 and −2 × 10 −9 year −1 . These low values may reflect a small amount of local deformation within the Sinai plate far from the main faults, although they could also result from a poor resolution or biases in our strain rates calculation (e.g., Pagani et al., 2021). Some discrepancies between the two approaches can be found along the DSF and in Jordan, east to the DSF.…”

“…It also provides the amount of interplate and intraplate deformation and variations of strain rates along the main faults. There are several techniques to assess the 2‐D strain rate tensor from geodetic measurements using different interpolation methods (see e.g., Baxter et al., 2011; Pagani et al., 2021 for comparison between different techniques). To compute the horizontal strain rate field, we interpolate the observed GPS velocity field using the GPSGRIDDER Module in the Generic Mapping Tools (GMT) software (Wessel et al., 2019).…”

Large‐Scale Interseismic Strain Mapping of the NE Tibetan Plateau From Sentinel‐1 Interferometry

“…Pagani et al. (2021) developed a Bayesian approach to extract strain rate from an ensemble of interpolated velocities derived from variable triangular meshes. However, these approaches all rely on some degree of low‐pass spatial filtering, hence do not incorporate the full information content of InSAR.…”

“…Kinematic block modeling ( e.g., Loveless & Meade, 2010;McCaffrey et al, 2013;Meade & Hager, 2005 ) is yet another approach that is often used to focus strain on predefined faults although the number of blocks tends to grow with the number of velocity measurements incorporated into the model. Pagani et al ( 2021 ) developed a Bayesian approach to extract strain rate from an ensemble of interpolated velocities derived from variable triangular meshes. However, these approaches all rely on some degree of low-pass spatial filtering, hence do not incorporate the full information content of InSAR.…”