Direct observation of channelling of induced currents

Abstract

The Cook Strait between the two main islands of New Zealand affords an excellent opportunity to study the channelling of induced oceanic electric currents between regions of much lower conductivity. We report here on simultaneous recordings of magnetic field variations on both islands and the voltage in a cable across the strait, which enabled us to determine the magnitude and direction of the channelled current. The observation of large currents approximately perpendicular to the direction expected in a homogeneous medium clearly demonstrates the dominance of channelling over local induction in the Strait. Copyright © 1987, Wiley Blackwell. All rights reserved