Description: Multibeam bathymetry raw data was recorded in the North Atlantic Ocean during cruise MSM75 that took place between 2018-06-29 and 2018-08-08. The data was collected using the ship's own Kongsberg EM 122. Sound velocity profiles (SVP) were applied on the data for calibration. SVP data are part of this dataset publication. This data is part of the DAM (German Marine Research Alliance) underway research data project.

Description: Multibeam bathymetry raw data was recorded in the North Atlantic during cruise MSM75 that took place between 2018-06-29 and 2018-08-08. The data was collected using the ship's own Kongsberg EM 712. This data is part of the DAM (German Marine Research Alliance) underway research data project. Underway data is collected continuously on German research vessels and can include data from transits or from the entire cruise. Underway data is shared in line with the FAIR principles.

Description: Hotspot-influenced spreading axes are characterized by a shallow axis, thickened crust, and possibly by higher-than-normal eruption frequency, all signs of an excess of magma and heat being supplied to such ridges by the hotspot. Despite this, these ridges are also characterized by an apparently lower-than-average incidence of high-temperature hydrothermal venting, raising questions about their thermal budget. The type example for hotspot-ridge interaction is the Reykjanes Ridge south of Iceland, which shows abnormally shallow bathymetry between the Reykjanes Peninsula at ca. 63°N and the Charlie Gibbs Fracture Zone at 53°N.The seafloor surrounding the present spreading axis is also characterized by V-shaped bathymetric ridges, thoughtto be produced by regions of excess melting migrating along the axis through time. Cruise MSM75aimed to produce geological maps of four key areas along the ridge -one with thickened crust where a V-shaped ridge intersects the present-day axis, one with thickened crust but no on-axis V-shaped ridge anomaly, a third with more normal crustal thickness and an axial valley and a fourth at the only known, but up to present unsampled, Reykjanes hydrothermal site Steinaholl. This geological mapping is to be usedto investigate questions of variations in eruption size or frequency away from Iceland, the interplay between magmatism and tectonism, the axial volcanology of V-shaped ridges and how thick crust is cooled in the apparent paucity of high-temperature vent fields.