​DIAS Geophysics, in collaboration with DIAS Astrophysics, will host a seminar by Dr. Juliane Huebert (British Geological Survey - Edinburgh, UK), who will present her work touching both Geo- and Astrophysics.

Title:
Differential magnetometer measurements of geo-magnetically induced currents in the UK power grid.

Abstract:
Extreme events of space weather can have severe effects on satellites and other technology in orbit, but also pose potential risk to ground-based infrastructure like power lines, railways and gas pipe lines through the induction of geo-magnetically induced currents (GICs). Modelling GICs requires knowledge about the source magnetic field and the conductivity structure of the Earth to calculate electric fields during enhanced geomagnetic activity. The electric field in combination with detailed information about the network topology enable the derivation of GICs in power lines. Directly monitoring GICs in power grid substations is possible with a Hall probe, but scarcely realised. In the UK, data from only four such stations located in Scotland is available at the moment. Therefore we have been deploying the differential magnetometer method (DMM) to measure GICs at various sites in the UK power grid, specifically in several high voltage network segments that appear as hotspots during electric field calculations for historic geo-magnetic storms due to their location within the network and the underlying of the British Isles.
The setup of the DMM includes the installation of two fluxgate magnetometers, one directly under a power line affected by GICs, and one as a remote site further away. The difference in recordings of the magnetic field in both instruments allows for the calculation of GICs in the respective power line segment. The recorded data are transferred back in real-time to the geomagnetic data centre in Edinburgh and compared to the predicted GICs. So far, we installed 3 such instruments and were able to capture GIC data during a G3 solar event in August 2018 that compares well with direct GICs measured in a nearby substation.