Fig. 4: Properties of the Bransfield Front.

a Locations of the mapped fronts (orange) in Fig. 3. b Water depth just beneath the frontal leading edge and the vertical extension of the front. c Apparent dip angle (gray, uncorrected) and the corrected dip angle (orange). d Geostrophic velocities estimated using the thermal wind equation with the density differences from WOD18 (\({U}_{g}\), gray) and Sangrà et al.¹⁸ (\({U}_{g}\), orange). The green line shows the result from a mass conservation scheme (\({U}_{m}\)). e The estimated Rossby number assuming the geostrophic velocity is 0.35 m/s for the uncorrected (gray) and the corrected (orange) length scales. The green line shows the results using \({U}_{m}\) in (d). Note that the lower x axes in (b–e) indicate the longitudes marked in (e), while the upper x axes show the front locations in (b), corresponding to the seismic lines in (a).