[ghsc-seminars] GHSC Seminar, **TODAY**, Thursday (10/18) @ 10am: Anna Kelbert, USGS

[Rigler, Erin (Josh)]

*The role of global/regional Earth conductivity models in natural
geomagnetic hazard mitigation*

*Anna Kelbert*
*U.S. Geological Survey, Golden *

Geomagnetic storms cause perturbations in the Earth's magnetic field which,
by the principle of electromagnetic induction, in turn cause electric
currents to flow in the Earth. These geomagnetically induced currents
(GICs) also enter man-made technological conductors that are grounded,
notably, telegraph systems, submarine cables and pipelines and the electric
power grid, where transformer groundings at power grid substations serve as
entry points for GICs. The strength of the GICs that flow through a
transformer depends on multiple factors, including the spatio-temporal
signature of the geomagnetic storm, the geometry and specifications of the
power grid, and the electrical conductivity structure of the Earth's
subsurface. Strong GICs are hazardous to power grids and other
infrastructure; for example, they can severely damage transformers and
thereby cause extensive blackouts. Extreme space weather is therefore
hazardous to man-made technologies. The phenomena of extreme geomagnetic
storms and their effects on human activity are commonly referred to as
geomagnetic hazards. Here, we provide a review of relevant GIC studies from
around the world, and describe their common and unique features, while
focusing especially on the effects that the Earth's electrical conductivity
has on the GICs flowing in the electric power grids. This is a repeat of a
keynote review talk given at the 24th EM Induction Workshop in Helsingør,
Denmark on August 17th, 2018.

*Thursday, October 18th**, 2018*
*10-11a*
*m*
*  (Mountain Time)*
*USGS, 1711 Illinois Street, Golden, CO*
*Entry Level Seminar Room (204)*

*Note: Please arrive *~5 minutes early* and *bring photo ID* for
airport-style security measures now in place at the USGS building.

Thank you,
GHSC Seminar Committee

Ben
Mirus - bbmirus at usgs.gov
Josh Rigler - erigler at usgs.gov
Oliver Boyd - olboyd at usgs.gov <oboyd at usgs.gov>
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