HR: 08:00h
AN: H21A-01 INVITED     [PDF]
TI: Recent Advances in the Use of Electrokinetic Self-Potential Signals as an Effective Tool in Hydrogeophysics to Monitor Ground Water Flow
AU: * Revil, A
EM: revil@cerege.fr
AF: CNRS-CEREGE, BP 80, Cedex 4, Aix-en-Provence, 13545 France
AU: Suski, B
EM: suski@cerege.fr
AF: CNRS-CEREGE, BP 80, Cedex 4, Aix-en-Provence, 13545 France
AU: Rizzo, E
EM: rizzo@cerege.fr
AF: CNRS-CEREGE, BP 80, Cedex 4, Aix-en-Provence, 13545 France
AU: Naudet, V
EM: naudet@cerege.fr
AF: CNRS-CEREGE, BP 80, Cedex 4, Aix-en-Provence, 13545 France
AB: Ground water flow generates detectable electrical signals at the ground surface through a conversion mechanism called streaming potential. These signals can be recorded in a passive way with a set of non-polarizable electrodes and a multi-electrode digital multimeter. These signals can be inverted to image the shape of the water table and its temporal variations using new self-potential tomography (SPT) algorithms. The signal-to-noise ratio seems high enough to expect an accuracy of 10 cm in the detrmination of the depth of the water table. Then, because the sensors are cheap, we can use an important number of measurement stations and we can obtain a great amount of information to invert in a cost-effective way. In this talk, we will discuss the physics of this hydro-electric and present both forward and backward methods to interpret field data. We will show examples from three field studies in which self-potential signals are associated with hydraulic head fluctuations. We will discuss the stability of the electrodes, the sources of noise, and new challenges in combining SPT with more classical electrical resistivity tomography (ERT).
DE: 0925 Magnetic and electrical methods
DE: 1832 Groundwater transport
DE: 5109 Magnetic and electrical properties
DE: 5114 Permeability and porosity
DE: 5139 Transport properties
SC: Hydrology [H]
MN: 2003 Fall Meeting