Processed high-resolution multi-channel seismic reflection (MCS) data from the CORE-VTRCC cruise (2021)

This data set consists of processed high-resolution multi-channel seismic reflection (MCS) data collected in 2021 over the Vitoria Trindade Ridge and Columbia Channel during research cruise CORE-VTRCC on naval vessel Nho Cruzeiro do Sul. The MCS data was acquired using a sparker seismic source with 800 tips model Geo-Source 800, up to 7 kJ energy power supply (GeoSpark 2000X) and a 48-channel streamer, all from the Geo Marine Survey Systems. Seismic acquisition and SEG-Y conversion was performed with the GeoRecorder software, also from Geo Marine Survey Systems. The Geo-Source 800 used a negative discharge for seismic pulse generation which results in a more stable seismic signature with a frequency range between 200 – 3000 Hz, centered at ~1 kHz. The streamer was composed of three hydrophones per channel, with a total active length of 150 m and 2 x 25 m cable stretches, to make a total of 200 m of streamer deployment. Channel distance in the streamer is 3.125 m and channel sampling occurred at 10 kHz. Geographic geometry was supplied by a DGPS antenna placed atop the seismic source configured with the WGS-84 ellipsoid and UTM projection zone 23S. Geometry distance averaged 5 m between source and streamer (dx) and ~20 m between source and first channel (dy). The source was placed at 1.5 m water depth and the streamer was at 0.5 m water depth. Energy levels and trigger interval for pulse generation varied across the survey depending on the bathymetric profile. Vessel velocity during seismic acquisition averaged 4 knots. Seismic processing was performed with the RadExPro software, v2022.1. Basic brutestack seismic processing was made for all seismic lines, following these steps: quality control (data filtering), preprocessing (noise filtering), geometry evaluation, normal move-out correction and stacking. For Lines L01 and L17 enhanced seismic processing was performed, including the following additional processing steps: static correction, deconvolution, multiple suppression and migration. Band-pass filtering was performed between 200 – 1500 Hz. For stacking, common mid points (CMD) gathers were established. See additional information in the associated Methodology report. The processed MCS files are in SEG-Y format. Funding for this work was provided through FAPESP awards 2016/24946-9 and 2020/08847-6, and through the Brazilian Navy program PROAMAZONIA AZUL.