The Contribution of Water Radiolysis to Marine Sedimentary Life
Abstract
Water radiolysis continuously produces H2 (an electron donor) and oxidized chemicals (electron acceptors) in wet sediment and rock. However, the extent to which radiolytic products sustain subseafloor ecosystems has been unclear. Our experiments show that all common marine sediment catalyzes radiolytic H2 production, amplifying H2 yields by up to a factor of 27 relative to pure water, depending on sediment composition. In electron equivalents, the global rate of radiolytic H2 production in marine sediment is approximately 1/10,000th the global rate of photosynthetic carbon fixation in the ocean. Comparison to organic oxidation rates suggests that water radiolysis is the principal source of electron donors and electron acceptors for microbial communities in marine sediment older than a few million years.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMEP54B..04S
- Keywords:
-
- 0448 Geomicrobiology;
- BIOGEOSCIENCES;
- 0495 Water/energy interactions;
- BIOGEOSCIENCES;
- 1829 Groundwater hydrology;
- HYDROLOGY;
- 5420 Impact phenomena;
- cratering;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS