Tidal influence on self-potential measurements

D. J.  MacAllister; M. D. Jackson; A. P.  Butler; J. Vinogradov

doi:10.1002/2016JB013376

Tidal influence on self-potential measurements

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

Engineering

Imperial College London

Research output: Contribution to journal › Article › peer-review

12 Citations (Scopus)

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Abstract

Long-term surface and borehole self-potential (SP) monitoring was conducted in the UK Chalk aquifer at two sites. The coastal site is c. 1.7 km from the coast and the inland site is c. 80 km from the coast. At both sites, power spectral density analysis revealed that SP data contain the main ocean tidal periodic components. However, the principal lunar component (M2), the dominant ocean tidal component, was most significant at the coastal site. The M2 signal in surface-referenced SP data at the inland site was partly due to telluric currents caused by the geomagnetic ocean dynamo. Earth and/or atmospheric tides also contributed, as the SP power spectrum was not typical of a telluric electric field. The M2 component in borehole-referenced data at the inland site was below the significance level of the analysis method and was two orders of magnitude smaller than the M2 signal in borehole-referenced SP data at the coastal site. The tidal response of the SP data in the coastal borehole is, therefore, primarily driven by ocean tides. These cause changes in fluid pressure and chemical concentration gradients within the coastal aquifer, leading to time varying electrokinetic and exclusion-diffusion potentials. Borehole-referenced SP measurements could be used to characterize and monitor tidal processes in coastal aquifers such as the intrusion of seawater.

Original language	English
Pages (from-to)	8432–8452
Number of pages	21
Journal	Journal of Geophysical Research: Solid Earth
Volume	121
Issue number	12
Early online date	10 Nov 2016
DOIs	https://doi.org/10.1002/2016JB013376
Publication status	Published - 1 Dec 2016

Bibliographical note

DJM was supported by NERC CASE studentship NE/I018417/1. The authors would also like to thank Southern Water for access to the borehole at Saltdean. Atkins Global and Southern Water are thanked for funding installation of the equipment and for additional funding under the NERC studentship. The laboratory components of this work were carried out in the TOTAL Reservoir Physics Laboratory at Imperial College London and their support is gratefully acknowledged. Jackson acknowledges partial support from TOTAL under the TOTAL Chairs programme. The data supporting the conclusions of this work are available through the corresponding author.

Keywords

self-potential
hydrogeophysics
tides
groundwater hydrology
electrokinetic potential
exclusion-diffusion potential
instruments and techniques : monitoring
magnetic and electrical methods
water management

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10.1002/2016JB013376Licence: CC BY

Tidal inﬂuence on self-potential measurements
©2016 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. https://creativecommons.org/licenses/by/4.0/
Final published version, 4.31 MBLicence: CC BY

Cite this

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title = "Tidal influence on self-potential measurements",

abstract = "Long-term surface and borehole self-potential (SP) monitoring was conducted in the UK Chalk aquifer at two sites. The coastal site is c. 1.7 km from the coast and the inland site is c. 80 km from the coast. At both sites, power spectral density analysis revealed that SP data contain the main ocean tidal periodic components. However, the principal lunar component (M2), the dominant ocean tidal component, was most significant at the coastal site. The M2 signal in surface-referenced SP data at the inland site was partly due to telluric currents caused by the geomagnetic ocean dynamo. Earth and/or atmospheric tides also contributed, as the SP power spectrum was not typical of a telluric electric field. The M2 component in borehole-referenced data at the inland site was below the significance level of the analysis method and was two orders of magnitude smaller than the M2 signal in borehole-referenced SP data at the coastal site. The tidal response of the SP data in the coastal borehole is, therefore, primarily driven by ocean tides. These cause changes in fluid pressure and chemical concentration gradients within the coastal aquifer, leading to time varying electrokinetic and exclusion-diffusion potentials. Borehole-referenced SP measurements could be used to characterize and monitor tidal processes in coastal aquifers such as the intrusion of seawater.",

keywords = "self-potential, hydrogeophysics, tides, groundwater hydrology, electrokinetic potential, exclusion-diffusion potential, instruments and techniques : monitoring, magnetic and electrical methods, water management",

author = "MacAllister, {D. J.} and Jackson, {M. D.} and Butler, {A. P.} and J. Vinogradov",

note = "DJM was supported by NERC CASE studentship NE/I018417/1. The authors would also like to thank Southern Water for access to the borehole at Saltdean. Atkins Global and Southern Water are thanked for funding installation of the equipment and for additional funding under the NERC studentship. The laboratory components of this work were carried out in the TOTAL Reservoir Physics Laboratory at Imperial College London and their support is gratefully acknowledged. Jackson acknowledges partial support from TOTAL under the TOTAL Chairs programme. The data supporting the conclusions of this work are available through the corresponding author.",

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AU - MacAllister, D. J.

AU - Jackson, M. D.

AU - Butler, A. P.

AU - Vinogradov, J.

N1 - DJM was supported by NERC CASE studentship NE/I018417/1. The authors would also like to thank Southern Water for access to the borehole at Saltdean. Atkins Global and Southern Water are thanked for funding installation of the equipment and for additional funding under the NERC studentship. The laboratory components of this work were carried out in the TOTAL Reservoir Physics Laboratory at Imperial College London and their support is gratefully acknowledged. Jackson acknowledges partial support from TOTAL under the TOTAL Chairs programme. The data supporting the conclusions of this work are available through the corresponding author.

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N2 - Long-term surface and borehole self-potential (SP) monitoring was conducted in the UK Chalk aquifer at two sites. The coastal site is c. 1.7 km from the coast and the inland site is c. 80 km from the coast. At both sites, power spectral density analysis revealed that SP data contain the main ocean tidal periodic components. However, the principal lunar component (M2), the dominant ocean tidal component, was most significant at the coastal site. The M2 signal in surface-referenced SP data at the inland site was partly due to telluric currents caused by the geomagnetic ocean dynamo. Earth and/or atmospheric tides also contributed, as the SP power spectrum was not typical of a telluric electric field. The M2 component in borehole-referenced data at the inland site was below the significance level of the analysis method and was two orders of magnitude smaller than the M2 signal in borehole-referenced SP data at the coastal site. The tidal response of the SP data in the coastal borehole is, therefore, primarily driven by ocean tides. These cause changes in fluid pressure and chemical concentration gradients within the coastal aquifer, leading to time varying electrokinetic and exclusion-diffusion potentials. Borehole-referenced SP measurements could be used to characterize and monitor tidal processes in coastal aquifers such as the intrusion of seawater.

AB - Long-term surface and borehole self-potential (SP) monitoring was conducted in the UK Chalk aquifer at two sites. The coastal site is c. 1.7 km from the coast and the inland site is c. 80 km from the coast. At both sites, power spectral density analysis revealed that SP data contain the main ocean tidal periodic components. However, the principal lunar component (M2), the dominant ocean tidal component, was most significant at the coastal site. The M2 signal in surface-referenced SP data at the inland site was partly due to telluric currents caused by the geomagnetic ocean dynamo. Earth and/or atmospheric tides also contributed, as the SP power spectrum was not typical of a telluric electric field. The M2 component in borehole-referenced data at the inland site was below the significance level of the analysis method and was two orders of magnitude smaller than the M2 signal in borehole-referenced SP data at the coastal site. The tidal response of the SP data in the coastal borehole is, therefore, primarily driven by ocean tides. These cause changes in fluid pressure and chemical concentration gradients within the coastal aquifer, leading to time varying electrokinetic and exclusion-diffusion potentials. Borehole-referenced SP measurements could be used to characterize and monitor tidal processes in coastal aquifers such as the intrusion of seawater.

KW - self-potential

KW - hydrogeophysics

KW - tides

KW - groundwater hydrology

KW - electrokinetic potential

KW - exclusion-diffusion potential

KW - instruments and techniques : monitoring

KW - magnetic and electrical methods

KW - water management

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DO - 10.1002/2016JB013376

M3 - Article

SN - 2169-9313

VL - 121

SP - 8432

EP - 8452

JO - Journal of Geophysical Research: Solid Earth

JF - Journal of Geophysical Research: Solid Earth

IS - 12

ER -

Tidal influence on self-potential measurements

Abstract

Bibliographical note

Keywords

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