HR: 08:00h
AN: B51F-01 INVITED     [Abstracts]
TI: Remote Sensing of Subsurface Microbial Transformations
AU: * Williams, K H
EM: khwilliams@lbl.gov
AF: University of California, Berkeley, Dept. Environmental Science, Policy and Management, Berkeley, CA 94720 United States
AU: * Williams, K H
EM: khwilliams@lbl.gov
AF: Lawrence Berkeley National Laboratory, Earth Sciences Division, Berkeley, CA 94720 United States
AU: Ntarlagiannis, D
EM: dimntar@pegasus.rutgers.edu
AF: Rutgers University, Dept. of Earth and Environmental Sciences, Newark, NJ 07102 United States
AU: Slater, L
EM: lslater@andromeda.rutgers.edu
AF: Rutgers University, Dept. of Earth and Environmental Sciences, Newark, NJ 07102 United States
AU: Long, P
EM: philip.long@pnl.gov
AF: Pacific Northwest National Laboratory, Box 999, Richland, WA 99352
AU: Dohnalkova, A
EM: Alice.Dohnalkova@pnl.gov
AF: Pacific Northwest National Laboratory, Box 999, Richland, WA 99352
AU: Hubbard, S S
EM: sshubbard@lbl.gov
AF: Lawrence Berkeley National Laboratory, Earth Sciences Division, Berkeley, CA 94720 United States
AU: Banfield, J F
EM: jill@eps.berkeley.edu
AF: University of California, Berkeley, Dept. Environmental Science, Policy and Management, Berkeley, CA 94720 United States
AB: Understanding how microorganisms influence the physical and chemical properties of the subsurface is hindered by our inability to detect microbial dynamics in real time with high spatial resolution. Here we have used non-invasive geophysical methods to monitor biomineralization and related processes during biostimulation at both laboratory and field scales. Alterations in saturated sediment characteristics resulting from microbe-mediated transformations were concomitant with changes in complex resistivity, spontaneous potential, and acoustic wave signatures. Variability in complex resistivity and acoustic wave amplitudes appears tied to the nucleation, growth, and development of nanoparticulate precipitates along grain surfaces and within the pore space. In contrast, time-varying spontaneous potentials appear primarily sensitive to the electrochemical gradients resulting from metabolic pathways, such as iron- and sulfate-reduction. Furthermore, they enable us to track mobile fronts of active respiration that arise due to microbial chemotaxis. In this way, geophysical data may be used to image the distribution of mineral precipitates, biomass, and biogeochemical fronts evolving over time and suggest the ability to remotely monitor contaminated aquifers undergoing bioremediation.
DE: 9820 Techniques applicable in three or more fields
DE: 5100 PHYSICAL PROPERTIES OF ROCKS
DE: 1894 Instruments and techniques
DE: 1615 Biogeochemical processes (4805)
DE: 0694 Instrumentation and techniques
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting