Figure 2
From: Reduced gravity promotes bacterially mediated anoxic hotspots in unsaturated porous media
Comparison of the water table, capillary fringe and extent of anoxic hotspots depending on the gravitational conditions. (A) Images of the pore network showing the upper extent of the water table (red) and the capillary fringe (orange) under five different conditions of gravity. (B) Optode camera images showing the extent of the anoxic conditions (blue dashed line) around the upper aggregate as it changes with gravitational conditions. An increase in water availability and resulting anoxia is mainly due to liquid supply via capillary forces when less strongly opposed by gravity, and the related diffusional constraint for oxygen.
