A map of relative P wave delay times across southern California

Abstract

Using cross correlation of band‐pass‐filtered waveforms, we have determined relative teleseismic P wave arrival times for the broadband stations in the Southern California Seismic Network (formerly known as TriNet). To remove as much as possible contamination of the direct P wave by near surface reflections and refractions, visible for arrivals at several stations located directly above complex three‐dimensional structures, we carried out this cross correlation over only the first quarter wavelength of the P waveform, after applying a 1–2 Hz Butterworth band‐pass filter. We subsequently completed a thorough visual and numerical quality control of the resulting traveltimes and were left with 12320 measurements for 144 events spanning a time period of almost 4 years, from 2000 to 2004. We present this complete data set on a topographic map of southern California (including a detailed inset map of the more densely covered LA basin area), enabling a direct investigation of data patterns. This visualization helps to develop an understanding of expected features of a future tomographic inversion of this data set.