During the cruise SO305/2 of the German research vessel SONNE, we recorded densely spaced magnetic field measurement over the Argo transform fault offsetting the Central Indian Ridge near 13°30'S. The total magnetic field was measured using two SeaSpy magnetometers which were towed at 500 m and 575 m, respectively, behind the stern of the ship, sampling the data continuously at 1 Hz. The ships navigation was corrected to match the position of the sensors towed behind the vessel and data were resampled at 30 s. Uncorrected total field magnetic data are available in text/ascii format.

Two magnetometers were towed behind the RV SONNE. The first sensor was 500 m behind the stern and the second sensor at 575 m. The magnetometers themself did not record geographical coordiates. Hence the GPS position of the vessel was used to assess their location. The GPS, at the center of the vessel, was 60 m away from the stern of the vessel and therefore 560 m and 635 m away from the first and second sensor, respectively. The coordinates of the sensors were then calclated at ~30s intervals an at the same time stamp.