Processed Seismic Navigation Data (P1 format) from Walvis Ridge and Valdivia Bank, South Atlantic Ocean (TN373, 2019)

This data set was acquired with the Scripps Institution of Oceanography portable multi-channel seismic system during a survey of Walvis Ridge and Valdivia Bank in the South Atlantic Ocean, as part of R/V Thomas G. Thompson cruise TN373 in late 2019. The data files presented here are in U.K.O.O.A. P1/90 format and contain Seismic Navigation data that was processed after acquisition. The purpose of cruise TN373 was to collect mutli-channel seismic reflection, magnetic, gravity, and bathymetric data over portions of Walvis Ridge as part of a site survey for International Ocean Discovery Program Expedition 391 and to study the formation of this hotspot trail. Owing to environmental regulations, however, seismic data were collected on one cruise (TN373) and multibeam echo-sounder data, magnetic data, and other geophysical data were collected on the subsequent cruise, TN374. Cruise TN373 started from Montevideo, Uruguay on 5 November 2019 and crossed the south Atlantic to Walvis Ridge. The Scripps portable seismic system used a 96-channel streamer with 2 small G-I airguns as the source. A short 114 km length seismic practice line was shot across southeastern Rio Grande Rise. After arrival in the Walvis Ridge Guyot Province, 13 seismic lines were run over guyots in three survey areas, totaling 717 km of profiles. At Valdivia Bank, an additional 13 seismic lines were run across this plateau feature, totaling 2,229 km of profiles. Altogether, the total number of seismic shots fired was 120,616 and the total length of profiling was 3015 km. Cruise TN373 was finished on 7 December 2019 after arrival at Walvis Bay, Namibia, where technical and science crew changes were made and the seismic gear was removed from the ship. The data set was acquired as part of the project called Tectonic evolution of the Rio Grande Rise - Walvis Ridge hotspot twins inferred from magnetic anomaly and seismic reflection data. Funding was provided by NSF award OCE18-32197.