Public awareness regarding the likely hazards associated with the detonation of an electromagnetic pulse (EMP) at high altitudes has been growing in recent years. But recent research provides a far more troubling prognosis of the potential damage that an EMP attack could cause on the global power infrastructure.
According to a recent article in the IEEE Spectrum, researchers at the U.S. Geological Survey (USGS) and the University of Colorado are working to better understand the totality of effects that can be created by a high-altitude EMP. The researchers used data collected from sensors and voltmeters deployed in a small region of mid-America, along with USGS research on the impact of magnetic storm disturbances in various regions across the U.S. with either electrically resistive or electrically conductive rock.
The USGS/University of Colorado research yielded some important new information on the varying impacts from a high-altitude EMP event. High-frequency pulses categorized as E1 would likely disrupt consumer electronic products, an aspect that already garners most of the public attention. Separately, electrical systems which are most vulnerable to E2 pulses are a concern, but such systems are increasingly being hardened to withstand E2 effects.
The problem is the E3 waveform, the part of the EMP signal operating at the lowest amplitude. According to the research, E3 pulses last the longest, ranging from about 0.1 seconds to several hundred seconds. This factor, along with the conductivity of the surrounding Earth and the specific parameters of the local electrical grid infrastructure, could lead to catastrophic damage to the power grid in complex geological settings.
As a result of their findings, the USGS/University of Colorado researchers have called for more research to analyze surface impedance across regions like the eastern mid-continent, as well as the eastern U.S. where the impact from magnetic storms is significant.