Robert M. Sare Felipe Aron Curtis W Baden Dave Caress Christopher M. Castillo Stephen C. Dobbs Jared T Gooley Samuel Johnstone Frances Liu Tim McHargue Josie M Nevitt Charles K. Paull Lauren E. Shumaker Miles M Traer Holly H Young George E. Hilley 2020 Transform faults are known to have anomalously low rates of seismicity, but no direct observations reveal why this is the case. We use new, autonomous underwater vehicle high-resolution seafloor mapping to image the morphology of and offsets along transform fault segments in the Gulf of California. Fault splays display a varied history of activation and deactivation of individual fault strands over time, not unlike those mapped onshore or imaged within the bathymetry of the Queen Charlotte-Fairweather and the Palos Verdes faults of offshore western Canada and Southern California. A series of six identically offset depositional fans evidence 21–23 meters of slip along the main transform fault, which could not have been produced by a single earthquake. Rather, the lack of smaller-magnitude offsets indicates synchronous deposition and an absence of multiple slope failure-inducing earthquakes, thus providing the first direct evidence that creep and earthquakes occur at different times in the slip history of a given transform fault segment. application/pdf 10.1130/G46663.1 en Geological Society of America Coexisting seismic behavior of transform faults revealed by high-resolution bathymetry article