FIGURE 6.

In situ microprofiler survey of orange Beggiatoa mat. (A) In situ profiler after placement on an orange Beggiatoa mat near Marker 14. Alvin heading 96, depth 2008 m, GMT 16:36:50, dive 4564, November 25, 2009. Temperature gradients were measured with the heat flow probe in two spots near the base of the profiler. The microsensor temperature profile matches the near-surface heat flow temperature profile plotted in yellow, but it is cooler than the nearby heat flow profile in red. (B) In situ profiler measurement of temperature, redox potential, oxygen, nitrate/nitrite, N₂O, H₂S, and total sulfides at orange mat location. (C) Sulfate, sulfide, and acetate porewater gradients from Alvin core 4564-14 taken in orange mat-covered sediment, marked by the number 14 in panel (A). Photographs courtesy of the Woods Hole Oceanographic Institution, from RV Atlantis cruise AT 15-56.