Son of Vera Rubin. Allan Rubin joined the faculty in 1992. He is a geophysicist who combines seismic and geodetic observations with numerical models, with the goal of improving our understanding of brittle deformation of the crust. Applications are primarily to regions of active volcanism and faulting. One of the major geophysical discoveries of the past decade has been that of "episodic slow slip and tremor" in many of the world's subduction zones. Most known faults either slip steadily at the plate tectonic rate, or spend most of the time "locked" and slip only during brief earthquakes, with slip speeds of order m/sec and propaga- tion speeds of order km/sec (the speed of sound in rock). Slow slip events, on the other hand, have average slip speeds of only ~01. m / s and propagate up to 300 km along strike at remarkably consistent rates of ~10 km/day. In terms of energy release they are comparable to magnitude 6-7 earthquakes, but they last for weeks rather than sec- onds. They have the additional remarkable property that they recur quasi-perio-dical- ly, at intervals ranging from several months to a few years, depending upon location. Coincident in time and space with the geodetically-observed slow slip is a new (to us) seismic signal termed "tectonic tremor". Unlike typical earthquakes, which have mi - pulsive P-wave and S-wave arrivals, tremor is a low-amplitude signal that can last for minutes to hours and that most often lacks clearly identifiable wave arrivals.