Geodetic Observation and Modeling of the Coseismic and Postseismic Deformations Associated With the 2020 Mw 6.5 Monte Cristo Earthquake

• Published in: Earth and space science (Hoboken, N.J.) N.J.), 2021-06, Vol.8 (6), p.n/a
• Main Authors: Li, Shuiping, Tao, Tingye, Chen, Yunguo, He, Ping, Gao, Fei, Qu, Xiaochuan, Zhu, Yongchao
• Format: Article
• Language: English
• Subjects: Aftershocks; Deflection; Deformation; Earthquakes; Fault lines; Global positioning systems; GPS; Kinematics; Satellites; Seismic activity; Time series
• ISSN: 2333-5084; 2333-5084
• DOI: 10.1029/2021EA001696

The 2020 Mw 6.5 Monte Cristo earthquake occurred in the northeastern Mina deflection of the central Walker Lane Belt (WLB) in Nevada, USA. The Mina deflection represents a typical stepover zone that transfers the dextral slip in the northern Eastern California Shear Zone onto the dextral faults in the central WLB. The Monte Cristo earthquake provides a rare opportunity to investigate the strain accumulation and stress transition mechanisms in the WLB. In this study, ascending and descending Sentinel‐1 images were utilized to generate coseismic and early postseismic deformations associated with this earthquake. Combined with global positioning system measurements, these images were inverted for the coseismic slip and afterslip of the Monte Cristo earthquake. The preferred coseismic slip model suggests that the causative fault is characterized by two fault segments with southward dips of 64° and 79°. The coseismic rupture was dominated by sinistral slip with obvious normal slip components in the western segment of the source fault. The coseismic slip was mainly concentrated in the 3–12 km depth range and decreased at shallower depths, suggesting a moderate amount of shallow coseismic slip deficit. Rapid afterslip was mainly confined to the 0–3 km depth range, largely compensating for the shallow slip deficit caused by the mainshock. The widely distributed normal slips in the northeastern Mina deflection revealed by the Monte Cristo earthquake suggest the transtensional model is more applicable due to its ability to account for the slip transition kinematics in the Mina deflection. Key Points Coseismic and postseismic displacements due to the Monte Cristo earthquake are mapped using interferometric synthetic aperture radar and global positioning system measurements The shallow slip deficit caused by the coseismic rupture is largely compensated by rapid afterslip The aftershocks are triggered by the stress change caused by both coseismic slip and rapid postseismic afterslip