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Electric potential variations associated with yearly lake level variations
Author(s) -
Perrier Frédéric,
Trique Michaël,
Lorne Benoit,
Avouac JeanPhilippe,
Hautot Sophie,
Tarits Pascal
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/98gl01139
Subject(s) - anomaly (physics) , water level , ridge , environmental science , magnitude (astronomy) , percolation (cognitive psychology) , geology , atmospheric sciences , hydrology (agriculture) , physics , geography , paleontology , cartography , geotechnical engineering , condensed matter physics , astronomy , neuroscience , biology
Electric potential variations have been recorded from November 1995 to February 1996 and continuously since October 1996 at 14 measurement points on a one km wide ridge separating two lakes in the French Alps. The levels of the lakes vary by several tens of meters on a yearly cycle, inducing stress variations and fluid percolation. At one point, unambiguous variations as large as 120 mV are observed over a year, linearly correlated with the levels of the lakes with a magnitude of 2 mV per meter of water level change. This particular measurement point lies at the edge of a SP anomaly, which supports the presence of a localized zone of ground water flow forced by the lake level, suggesting an electrokinetic mechanism. The observed correlation implies a ζ‐potential of the order of ‐8 mV for a 60 Ωm electrolyte, in agreement with laboratory measurements.