Self-potential (SP) response to seawater intrusion in coastal aquifers

D.J. MacAllister, M.D. Jackson, A.P. Butler, Jan Vinogradov

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Seawater intrusion is a major threat to the sustainability of coastal water supplies. Long-term self-potential (SP) monitoring has been conducted on the South-Coast of the UK in the chalk aquifer, in order to test its application for remote detection of the saline front. Tidal SP fluctuations of c. 2mV have been observed. We attribute tidal SP fluctuations to the exclusion potential, caused by the salinity gradient and the movement of the saline front in the chalk matrix. Furthermore we observe a systematic increase in SP beginning 5 days prior
to saline breakthrough; with a maximum magnitude of 300µV at the base of the borehole. We attribute this to the diffusion potential, generated by the local movement of saline water through a fracture logged close to the location of the maximum SP change. These results suggest, for the first time, that SP can provide early warning of seawater intrusion
Original languageEnglish
Title of host publicationProceedings of the 23th Salt Water Intrusion Meeting
PublisherSWIM
Number of pages4
Publication statusPublished - 2014
Event23rd Salt Water Intrusion Meeting - Husum, Germany
Duration: 16 Jun 201420 Jun 2014

Conference

Conference23rd Salt Water Intrusion Meeting
Abbreviated titleSWIM 2014
CountryGermany
CityHusum
Period16/06/1420/06/14

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MacAllister, D. J., Jackson, M. D., Butler, A. P., & Vinogradov, J. (2014). Self-potential (SP) response to seawater intrusion in coastal aquifers. In Proceedings of the 23th Salt Water Intrusion Meeting SWIM.