SCEC Award Number 24142 View PDF
Proposal Category Collaborative Research Project (Multiple Investigators / Institutions)
Proposal Title QUANTIFYING FAULT SLIP PARTITIONING BETWEEN THE CALAVERAS AND HAYWARD FAULTS, CA Part I - New Insights from Neotectonics and 10Be dates and rates*
Investigator(s)
Name Organization
Elizabeth Madden San Jose State University Kimberly Blisniuk San Jose State University
SCEC Milestones A1-1, A3-1, A1-3, A3-4 SCEC Groups Geology, FARM, SDOT
Report Due Date 03/15/2025 Date Report Submitted 07/25/2025
Project Abstract
 10 Be-derived catchment-wide erosion rates for 15 watersheds between the Calaveras and Hayward Faults range from 0.047 mm/y to 0.161 mm/yr, appear to support a landscape that is in topographic equilibrium. We find that low erosion rates from the southern Diablo Mountains, where the Calaveras Fault steps left to the Hayward Fault, are consistent with similarly low mean slope, low local relief (100m and 1500m) and low ksn values. This pattern suggests that crustal uplift and overall topography may control erosion rates here. Second, we find that 10 Be-derived erosion rates from the southern Diablo Mountains may reflect variations from increased tectonic uplift from south to north. In landscapes that are in topographic equilibrium, it is expected that hillslopes and channels are coupled, and the topographic metrics representing channel steepness and hillslope gradient show similar patterns with erosion rates. These data suggest that fault geometry and active faulting may have a strong influence on the landscape as this region is a restraining bend that is accommodating transpression between the Calaveras and Hayward Faults.
Intellectual Merit This project contributed to the intellectual merit of SCEC by advancing earthquake geology science in Northern California by:
- assessing and improving the quality of the SCFM (A1-1, A3-1);
- reconciling inconsistencies between the SCFM and the National Seismic Hazard Model (NSHM) faults [Hatem et al., 2022] (A3-1);
- identifying locations across the SAF System in the southern Bay Area where new paleoseismic observations will best constrain surface rupture behavior (A1-3); and
- constraining slip rates in populated areas (A3-4).
Broader Impacts This project supported 2 MS graduate students and 1 undergraduate student at SJSU.
Project Participants Elizabeth Madden - Advisor
Simone Yaeger - MS graduate student
Duncan Lord - MS graduate student
Exemplary Figure Figure 3. Results of denudation rates along Hayward Fault: Erosion rates displayed on hillshade map from junction of Hayward and Calaveras faults to Calaveras Fault terminus in north . Fault lines are (USGS, 2004): Arroyo Aguague Fault (AAF) black, Mission Fault (MF) green, Hayward Fault (HAF) red, and Calaveras Fault (CAF) brown. Fault slip rates are given in parentheses. Erosion rates (cool to warm colors) increase from southeast to northwest and decrease in northernmost basins. Denudation rates from east to west and north to south show how slip is partitioned from Calaveras to Hayward fault in southern restraining step.
Linked Publications

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