Induced Electric Currents in the Alaska Oil Pipeline Measured by Gradient Fluxgate and SQUID Magnetometers

Fluxgate magnetometers in a gradient alignment and a gradient superconducting quantum interference device (SQUID) magnetometer were used to determine the current induced in the Alaska oil pipeline during a period of geomagnetic disturbance. The measurements compared favorably to each other and to the nearby current deterninations using a shunt connected directly to the pipe.