Chapter 2 - Global Characteristics of Oceanic Transform Fault Structure and Seismicity

Abstract

On mid-ocean ridge-bounded oceanic transform faults (RTFs), previous characterizations of seismicity have utilized the assumed structural simplicity to develop scaling relations between tectonic (fault length and slip rate) and seismic parameters, which have shown that RTFs have low seismic coupling and small maximum magnitudes, despite large fault areas. These studies, however, did not incorporate physical segmentation of the fault trace. Here, we present an updated global characterization of oceanic transform fault structure and use the results to inform an updated scaling analysis. The inclusion of physical segmentation in the analysis does not significantly affect the scaling relations, indicating that segmentation alone cannot account for the low seismic coupling or small earthquake sizes on RTFs. We conclude that varying mechanical properties along the fault must largely control the partitioning of seismic and aseismic slip on RTFs.