2018 San Diego Trough fault CSULB multichannel seismic reflection data

The multichannel seismic reflection survey was conducted on the R/V Point Loma under Captain Neal Driscoll during agreeable weekend weather windows in April 2018. The science party consisted of PIs Bormann (UNR/CSULB) and Kent (UNR), and Scripps Institution of Oceanography postdoc Hector Perea and students Boe Derosier, Colby Nicholson, and Daniel Schwartz. The survey was conducted over three single-day trips, with the vessel departing and returning to San Diego daily. We collected six new profiles totaling 50 line-km of high-resolution multichannel seismic reflection data (Figure 2 – purple grid). The data were acquired using California State University’s 16-channel digital Geo-Eel hydrophone streamer with 6.25 m group spacing and a 2-kJ three-tip sparker energy source. Both the source and the streamer were towed at 3 m depth, with a near offset of 25 m. The survey speed ranged between 4.0-4.2 knots in favorable weather conditions with swells of less than 1m. 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, 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