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

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 ± 0.5 mm/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.

Research Highlights► 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.