Can we reliably resolve near-fault complexity along the creeping central San Andreas with high-resolution lidar differencing?

Catherine E. Hanagan, Stephen DeLong, Jessie Vermeer, Morena Hammer, & Chelsea P. Scott

Submitted August 30, 2026, SCEC Contribution #15278, 2026 SCEC Annual Meeting Poster #058

The central San Andreas fault has an exceptional geodetic record, with high-precision measurements of near-fault (10s to 100s m) surface fault creep dating to the late 1960s from sparsely distributed (multi-km) alignment arrays and creepmeters. Recent re-measurement of the arrays extend the record of fault creep to present day, complemented by InSAR and differential lidar point-cloud measurements that fill spatial gaps along-strike. Together, these records reveal spatially comprehensive and relatively consistent multi-year to multi-decade records of creep rates on the order of 1-3 cm/yr. However, the variability of fine-scale surface creep (sub-metric resolution) is not well-resolved. Additionally, the location of creep revealed from geodetic methods is not always co-located with the strongest geomorphic indicators of active faulting. Differences can reveal subtle deviations from the often-inferred simple fault geometry, and may hint at long-term fault slip evolution. We compare 0.5-m resolution displacements derived from 11-year repeat airborne lidar digital elevation models with updated alignment array measurements and geomorphic fault expression. This analysis will help to determine whether we can reliably detect kinematic complexity over the course of 11 years on the creeping fault, and how our observations compare with the decadal geodetic and thousands-to-millions of years geomorphic record. Results may also help to establish expectations for lidar differencing once new data are collected in 2026 over the central San Andreas.

Key Words
Creep, San Andreas, Lidar Differencing, High-resolution Displacement Detection

Citation
Hanagan, C. E., DeLong, S., Vermeer, J., Hammer, M., & Scott, C. P. (2026, 08). Can we reliably resolve near-fault complexity along the creeping central San Andreas with high-resolution lidar differencing?. Poster Presentation at 2026 SCEC Annual Meeting.

Related Projects & Working Groups
Stress and Deformation Over Time (SDOT)