loading page

Characteristic Slow-Slip Events on the Superstition Hills Fault, Southern California
  • +5
  • Ellis Vavra,
  • Yuri Fialko,
  • Thomas K. Rockwell,
  • Roger Bilham,
  • Petra Stepancikova,
  • Jakub Stemberk,
  • Petr Tábořík,
  • Josef Stemberk
Ellis Vavra
Scripps Institution of Oceanography

Corresponding Author:[email protected]

Author Profile
Yuri Fialko
Author Profile
Thomas K. Rockwell
San Diego State University
Author Profile
Roger Bilham
CIRES, Univ Colorado, Department of Geological Sciences
Author Profile
Petra Stepancikova
Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic
Author Profile
Jakub Stemberk
Institute of Rock Structure and Mechanics of the Czech Academy of Sciences
Author Profile
Petr Tábořík
Charles University, Faculty of Science, Institute of Hydrogeology, Engineering Geology and Applied Geophysics
Author Profile
Josef Stemberk
Department of Engineering Geology, Institute of Rock Structure & Mechanics, v.v.i.
Author Profile


The Superstition Hills Fault (SHF) exhibits a rich spectrum of slip modes, including M 6+ earthquakes, afterslip, quasi-steady creep, and both triggered and spontaneous slow slip events (SSEs). Following 13 years of quiescence, creepmeters recorded 25 mm of slip during 16-19 May 2023. Additional sub-events brought the total slip to 41 mm. The event nucleated on the northern SHF in early-May and propagated bi-laterally at rates on the order of kilometers per day. Surface offsets reveal a bi-modal slip distribution, with slip on the northern section of the fault being less localized and lower amplitude compared to the southern section. Kinematic slip models confirm systematic variations in the slip distribution along-strike and with depth and suggest that slip is largely confined to the shallow sedimentary layer. Observations and models of the 2023 SSE bear a strong similarity to previous slip episodes in 1999, 2006, and 2010, suggesting a characteristic behavior.
05 Dec 2023Submitted to ESS Open Archive
10 Dec 2023Published in ESS Open Archive