We employ seismic reflection, magnetics, and electromagnetics to locate precisely the southern extension of the Pahrump Valley Fault Zone (PVFZ) and examine its subsurface geometry. The southern extension of the PVFZ is active and represents a potential seismic hazard for Las Vegas. We observe pronounced magnetic and conductivity anomalies, and truncations of reflectors in the seismic profiles coincident with one of three Holocene scarps in southern Pahrump Valley. These geophysical techniques in combination can locate faults more precisely than the presence of eroded scarps.

We examine seismic signals from tsunamis for 14 earthquakes of Mw 7.1 to 8.4 in the circum‐Pacific region that generated tsunamis measured previously from tide gauges or coastal runup. Low‐frequency signals of 0.5 mHz up to 2–8 mHz are observed at the expected tsunami arrival time on the horizontal components of low elevation seismic stations near coastlines for eight of the 14 earthquakes. Lower amplitude signals are observed for the other six. For two earthquakes (Mw 8.2–8.4) we observe a dispersed tsunami signal between 1 and 8 mHz, with lower frequencies arriving earlier. This dispersion is consistent with predictions from the standard model for gravity waves for the bathymetry along these source‐station paths. These observations, along with earlier observations from the Indian Ocean, suggest that seismic data could be used to complement tide gauges and ocean bottom pressure recorders to indicate the arrival of a tsunami.