| Title: |
Monitoring experimentally induced saline intrusion through vertical self potential profiling at costal aquifer in Northern Ireland |
| Authors: |
Rowan, Tom; McDonnell, Mark; Aguila, Jesus; Benner, Eric; Butler, Adrian; Jackson, Matthew; Tompson, Chris; Flynn, Raymond; Donohue, Shane; Hamill, Gerry |
| Source: |
Rowan, T, McDonnell, M, Aguila, J, Benner, E, Butler, A, Jackson, M, Tompson, C, Flynn, R, Donohue, S & Hamill, G 2022, 'Monitoring experimentally induced saline intrusion through vertical self potential profiling at costal aquifer in Northern Ireland', European Geosciences Union General Assembly 2022, Vienna, Austria, 23/05/2022 - 27/05/2022. https://doi.org/10.5194/egusphere-egu22-12754 |
| Publication Year: |
2022 |
| Collection: |
Queen's University Belfast: Research Portal |
| Description: |
Due to greater ground-water abstraction, rising demand for water, possible reductions in recharge rates and rising sea levels, costal aquifers are under ever increasing threat of Saline Intrusion (SI) (Mehdizadeh, 2019). Though the mechanismins of SI have long been understood, the ability to monitor and warn in advance of the ingress of saline water into costal aquifers has remained costly and complex (Graham, 2018). The work reported here describes initial efforts to develop and results from, a vertically profiling Self Potential (SP) device. The device was used to monitoring the position of a well parametrized saline front in a costal aquifer, located on Benone Strand, Co. Derry, on the northern tip of Northern Ireland, UK, as part of the SALine INtrusion in coastal Aquifers project. Naturally arising voltages, Self Potential (SP), are formed when pressure and concentration gradients move though the subsurface. The gradients cause ion separations, which create electrical potentials and a flow of electrons in order to maintain electrical neutrality. The SP signals (usually in the millivolt range) can be detected, relatively inexpensively (in comparison to resistivity imagining) with reference electrodes and a high impedance voltage logger. The positioning of the electrodes is key as it has only been possible, until now, to measure the voltage between two points. There are two key types of SP, in hydrology, electro-kinetic potentials (VEK), due to differential flow velocities, and exclusion-diffusion potentials (VED), due to ion concentration gradients with different mobilities. Understanding the source mechanims in these voltages is complex, but evolving. Previous work has shown that self-potential rises before a saline breakthrough into a borehole (Graham, 2018). A novel vertically travelling (or trolling) SP electrode was repeatedly used in a number of satellite boreholes during a pumping test; in order to look at the changes in the vertical gradient of SP. The pumping test took place over three days, during ... |
| Document Type: |
conference object |
| Language: |
English |
| DOI: |
10.5194/egusphere-egu22-12754 |
| Availability: |
https://pure.qub.ac.uk/en/publications/a2e380fe-b23e-4bf7-9c88-cba02f93686d; https://doi.org/10.5194/egusphere-egu22-12754 |
| Rights: |
info:eu-repo/semantics/openAccess |
| Accession Number: |
edsbas.651DF7D2 |
| Database: |
BASE |