2018 San Pedro Basin fault CSULB multichannel seismic reflection data

The multichannel seismic reflection survey was conducted on the R/V Yellowfin under Captains Dennis Dunn and Joel Ingram. The science party consisted of PIs Bormann (CSULB) and Kent (UNR), and graduate students from California State University, Long Beach and the Scripps Institution of Oceanography. The survey was conducted in a series of one-day cruises between Los Angeles Harbor and Two Harbors on Catalina Island during April-June 2018. In total, the survey consisted of 10 days of marine seismic reflection data acquisition. We collected 33 new profiles totaling 365 line-km of high-resolution multichannel seismic reflection data. We acquired the data using California State University-Long Beach’s 16-channel digital Geo-Eel hydrophone streamer with 6.25 m group spacing and a 2-kJ three-tip sparker energy source. We towed both the source and the streamer at 3 m depth, with a near offset of 25 m. The survey speed ranged between 4.0-5.0 knots in favorable weather conditions with swells of less than 2 m. The shot interval was 3 seconds, resulting in a nominal common mid-point spacing of 3.125 m. The reflected waveforms were sampled at 0.5 ms intervals for 2.5 seconds to image roughly twice the maximum seafloor depth. We processed the data using a combination of Matlab and Sioseis (Henkart, 2003). The processing workflow consisted of (1) assigning source and receiver geometry to the shot records, (2) trace editing, (3) sorting the shot gathers to create CMP gathers, (4) minimum-phase bandpass filtering (5) applying a normal moveout correction, (6) stacking the CMP gathers into single CMP traces, and (7) frequency-wave number (f-k) migration. All processing and travel-time to depth conversions in this paper assume water column and sediment velocities of 1500 m/s. The processed data contain acoustic frequencies between 20-150 Hz or 50-200 Hz (as labeled in the processed segy file names), resulting in a vertical resolution of ~3-5 m with maximum penetration over 1000 ms (~750 m) beneath the seafloor. Contents: raw (shot gathers) mcs data (segy format), processed (post-stack migrated) mcs data (segy data), navigation files (WGS-84): shot-time locations (.ts) and reflection point (.rp), line plots