Geophysical Modelling of Geomagnetically Induced Currents in the UK

Geomagnetically Induced Currents (GICs) occur during large geomagnetic storm events, typically triggered when a coronal mass ejection from the Sun encounters the Earth's magnetic field. These GICs flow through the conductive crust of the Earth and take 'easy' low resistance paths, such as those through the grounded elements of the UK power grid. Currents flowing directly through the high-voltage network, may cause damage to electrical equipment including transformers. Monitoring of changes in the geomagnetic field, in concert with detailed modelling of the power network and the conductivity of crustal rocks, allows predictions to be made of GICs at particular locations. These predictions are of great interest to power grid operators, as asset owners, and Government, which is concerned that critical infrastructures are resilient to the impacts of natural hazard events. BGS has had several projects looking at various aspects of this problem. We propose to join together three separate threads of research to produce a single model which takes magnetic field data from BGS (and other) observatories, a representative conductivity model of the UK, and the physical configuration of the National Grid as inputs, and outputs a prediction of GICs at transformer sites nationwide.

We want to investigate how well our understanding of the geophysics matches with measurements of these GICs made at transformer sites. We wish to investigate what might happen if an extreme geomagnetic storm were to occur, including the maximum size of currents induced in the electrical grid. This information would be extremely useful to operators of power, communication, and oil/gas networks, for example.

The research from this project will be of both direct and indirect benefit to the UK economy and society as a whole. Prevention of damage to vital infrastructure during large geomagnetic events is, of course, very much in the national interest. Maintenance of electrical power and communications networks are essential to modern society. The results from natural hazards research into this topic will have a long-lasting impact.

The UK Government has given high priority to ensuring the resilience of critical infrastructures (c.f. recent publications from the Cabinet Office and the Treasury). A recent meeting of the Science and Technology Select Committee considered space weather impacts and the Director of Network Operations at National Grid was called to give oral evidence. Results from this research will be delivered as published papers and presentations to interested stakeholders, and will provide evidence for the National Risk Assessment, carried out by the Cabinet Office and for any further UK government inquiries.

The UK power industry sector is an obvious user and beneficiary. The PI will organise meetings with BGS contacts in the power sector to advertise the research, results and developments being made, as it is very important that industry support and interest is maintained. Other beneficiaries are oil and gas network operators as well as rail and other communication network operators, for example.