Extended Data Fig. 2: Gotland Basin Northern transect.
From: Methane leakage through the sulfate–methane transition zone of the Baltic seabed
a) Acoustic transect and core locations (black arrows). The stratigraphy is same as in Fig. 1 caption. Inset profiles are from Stations 73, 57, and 56 in full CH4 scale. Methane data that may be compromised by degassing are indicated by (+) symbols. b) Sulfate and methane profiles from stations along the transect. Methane profiles are shown with expanded scale. The black dashed lines indicate the SMT depth. Values of RSWI/SMT show how much methane leaks from the SMT to the SWI. In panel for Stations 73 and 56, the faint red line connects the deeper methane concentration which is off scale, but can be seen in panel A inset.
