Fig. 1: Depth profile of groundwater at Olkiluoto.
From: Active anaerobic methane oxidation and sulfur disproportionation in the deep terrestrial subsurface
Concentration of (A) total dissolved solids (TDS), B Sulfate. C Methane. D Hydrogen. Opposing trends in sulfate and methane concentrations with depth create an SMTZ at ~250–350 meters below sea level (mbsl). Filled diamonds indicate data from drill hole OL-KR13 (fracture at 330.52–337.94 mbsl) and open circles show baseline values from characterization and monitoring of the Olkiluoto site (1994–2018). Hydrogen concentrations below the detection limit are not shown. Data was provided by Posiva Oy.
