Poster #016, Earthquake Geology

How does climate affect the evolution of offset channels on strike-slip faults? Insights from landscape evolution models

Nadine G. Reitman, Karl J. Mueller, & Greg Tucker
Poster Image: 

Poster Presentation

2020 SCEC Annual Meeting, Poster #016, SCEC Contribution #10704
Offset geomorphic piercing points, such as stream channels, are commonly used to determine fault slip rates from historical and paleoseismic earthquakes, under the assumption that they record coseismic slip. Though researchers dating back to Wallace (1968) recognize that both tectonic and geomorphic factors control the appearance and preservation of offset channels on strike-slip faults, few studies have systematically explored the development of offset channels through multiple earthquake cycles under different climatic settings. In this project, we use numerical landscape evolution models to explore the relation between diffusion rate and slip rate on the formation and evolution of offset channels through multiple earthquake cycles. In doing so, we simulate the effects of three different climates on offset channel formation and preservation. We build on prior work that observed that offset channels underestimate modelled fault slip when measured many years after an earthquake to explore if that observation holds true for a variety of climatic environments and slip rates and evaluate how well and for how long the geomorphic record retains reliable information on large surface rupturing earthquakes. We hope the results of this work will help inform interpretation and measurement of offset piercing points for paleoseismic earthquakes.