Acceleration and evolution of faults: An example from the Hunter Mountain–Panamint Valley fault zone, Eastern California

• Published in: Earth and planetary science letters Vol. 301; no. 1-2; pp. 337 - 344
• Main Authors: Gourmelen, Noel, Dixon, Timothy H., Amelung, Falk, Schmalzle, Gina
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 03.01.2011
• Subjects: Eastern California Shear Zone; Estimates; Evolution; fault evolution; Faults; geodesy; Geology; Hunter Mountain Fault; InSAR; Mountains; Offsets; rock mechanics; Slip; Valleys; Western United States; Hunter Mountain Fault; fault evolution; rock mechanics; Eastern California Shear Zone; InSAR; Western United States; geodesy
• ISSN: 0012-821X; 1385-013X
• DOI: 10.1016/j.epsl.2010.11.016

We present new space geodetic data indicating that the present slip rate on the Hunter Mountain–Panamint Valley fault zone in Eastern California (5.0±0.5mm/yr) is significantly faster than geologic estimates based on fault total offset and inception time. We interpret this discrepancy as evidence for an accelerating fault and propose a new model for fault initiation and evolution. In this model, fault slip rate initially increases with time; hence geologic estimates averaged over the early stages of the fault's activity will tend to underestimate the present-day rate. The model is based on geologic data (total offset and fault initiation time) and geodetic data (present day slip rate). The model assumes a monotonic increase in slip rate with time as the fault matures and straightens. The rate increase follows a simple Rayleigh cumulative distribution. Integrating the rate-time path from fault inception to present-day gives the total fault offset. ► We provide slip rate estimate for the Hunter Mountain fault, Eastern California Shear Zone. ► We propose a quantitative model for fault evolution based on easily measured field parameters. ► This model provides guidance on comparison of geodetic vs geologic fault slip rate data.