Recently completed geophysical survey will help protect critical infrastructure from geomagnetic storms and space weather

The U.S. magnetotelluric array provides important geophysical information about the Earth’s electrical structure, which will aid in hazard assessments, such as those addressing the effects of geomagnetic storms and space weather on the electric grid.

The U.S. Geological Survey collaborated with the National Science Foundation, NASA, the EarthScope Consortium, Oregon State University and others to complete this work, which also helps support mineral and geothermal resource assessments.

“The USMTArray data are giving us amazing insights into how our planet works.” Gavin Hayes, senior science advisor for geohazards at the U.S. Geological Survey, said“And this tool has countless applications across industry, government and academia.”

Magnetotellurics is a geophysical technique that maps the electrical conductivity of rocks in the Earth’s crust and upper mantle.

The geoelectric field model, which is composed of USMTArray data and real-time geomagnetic field data provided by the U.S. Geological Survey Geomagnetic Program, shows the current condition of the Earth’s electric field (“geoelectric hazard analysis”) so power system engineers can assess the vulnerability of critical infrastructure, especially during geomagnetic storms. Geomagnetic storms generate currents that can damage transformers and cause cascading blackouts. With access to near real-time information, engineers can adjust operations and avoid potential blackouts or other disruptions.

“It took us a long time and a remarkable group of people to make this happen.” Adam Schultz, a researcher at Oregon State University and former project leader, said“We are very proud to have completed this survey and to have published this data.”

The USMTArray includes data from nearly 1,800 sites across the contiguous United States and has already inspired a wealth of valuable research—including studies of the geologic structure of the Appalachian Mountains, imaging fluid circulation beneath the western United States, locating ancient suture zones beneath the Great Plains, mapping the nation’s critical mineral potential, and imaging the deep roots of iconic volcanoes such as Yellowstone.

This rich dataset will be mined for decades to come, informing hazard and resource assessments, illuminating the nation’s geological framework, and serving as the backbone for more detailed investigations.