Imperial College London

ProfessorMatthewJackson

Faculty of EngineeringDepartment of Earth Science & Engineering

TOTAL Chair in Geological Fluid Mechanics
 
 
 
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Contact

 

+44 (0)20 7594 6538m.d.jackson

 
 
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Location

 

1.34Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Malcolm:2018:10.1029/2018WR022972,
author = {Malcolm, G and Jackson, M and MacAllister, DJ and Vinogradov, J and Butler, AP},
doi = {10.1029/2018WR022972},
journal = {Water Resources Research},
pages = {6055--6071},
title = {Self-potential as a predictor of seawater intrusion in coastal groundwater boreholes},
url = {http://dx.doi.org/10.1029/2018WR022972},
volume = {54},
year = {2018}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - Monitoring of selfpotentials (SP) in the Chalk of England has shown that a consistent electrical potential gradient exists within a coastal groundwater borehole previously affected by seawater intrusion (SI) and that this gradient is absent in boreholes further inland. Furthermore, a small but characteristic reduction in this gradient was observed several days prior to SI occurring. We present results from a combined hydrodynamic and electrodynamic model, which matches the observed phenomena for the first time and sheds light on the source mechanisms for the spatial and temporal distribution of SP. The model predictions are highly sensitive to the relative contribution of electrochemical exclusion and diffusion potentials, the ‘exclusion efficiency’, in different rock strata. Geoelectric heterogeneity, largely due to marls and hardgrounds with a relatively high exclusion efficiency, was the key factor in controlling the magnitude of the modelled SP gradient ahead of the saline front and its evolution prior to breakthrough. The model results suggest that, where sufficient geoelectric heterogeneity exists, borehole SP may be used as an early warning mechanism for SI.
AU - Malcolm,G
AU - Jackson,M
AU - MacAllister,DJ
AU - Vinogradov,J
AU - Butler,AP
DO - 10.1029/2018WR022972
EP - 6071
PY - 2018///
SN - 0043-1397
SP - 6055
TI - Self-potential as a predictor of seawater intrusion in coastal groundwater boreholes
T2 - Water Resources Research
UR - http://dx.doi.org/10.1029/2018WR022972
UR - https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018WR022972
UR - http://hdl.handle.net/10044/1/62718
VL - 54
ER -