 The growth faults in the region strike N15E, have steep dips (~70 deg), and vertical displacements of 1–4 mm/yr.Eight large slip events have occurred on these faults with throw ranging from 0.2–1.0 meters.These produce earthquakes greater than magnitude six and are responsible for the majority of extension in the basin and consequently thermal anomalies, subsidence, and localization of rhyolite buttes such as the Salton Buttes.