This 2016 R/V Langseth collected seismic reflection and refraction data along a single flowline from the Mid-Atlantic Ridge (MAR) to the Rio Grande Rise in support of the Crustal Reflectivity Experiment Southern Transect (CREST) project. 5 crossline profiles (isochrons) corresponding with the OBS lines, and 2 extra lines crossing (normal to) the ridge were also acquired. An IODP site survey, the objectives included studying the fundamental structure and evolution of oceanic crust, comparing the seismic structure versus the lithology.