We present evidence of a geobattery associated with microbial degradation of a mature crude oil spill. Self-potential measurements were collected using a vertical array of nonpolarizing electrodes, starting at the land surface and passing through the smear zone where seasonal water table fluctuations have resulted in the coating of hydrocarbons on the aquifer solids. These passive electrical potential measurements exhibit a dipolar pattern associated with a current source. The anodic and cathodic reactions of this natural battery occur below and above the smear zone, respectively. The smear zone is characterized by high magnetic susceptibility values associated with the precipitation of semiconductive magnetic iron phase minerals as a by-product of biodegradation, facilitating electron transfer between the anode and the cathode. This geobattery response appears to have a transient nature, changing on a monthly scale, probably resulting from chemical and physical changes in subsurface conditions such as water table fluctuations.
J. W. Heenan et al., "Field-Scale Observations of a Transient Geobattery Resulting from Natural Attenuation of a Crude Oil Spill," Journal of Geophysical Research: Biogeosciences, vol. 122, no. 4, pp. 918-929, American Geophysical Union (AGU), Apr 2017.
The definitive version is available at https://doi.org/10.1002/2016JG003596
Geosciences and Geological and Petroleum Engineering
Enbridge Energy Partners
Minnesota Pollution Control Agency
U.S. Geological Survey Toxic Substances Hydrology Program
United States. Environmental Protection Agency
Keywords and Phrases
Biogeobattery; Biogeophysics; Geobattery
International Standard Serial Number (ISSN)
Article - Journal
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