Abstract

By monitoring perturbations of the natural atmospheric electric potential gradient, it is possible to detect and track particle laden volcanic plumes. The perturbations are produced by electrical charge that resides on the solid particles and liquid droplets of the plume, and the ions within it. A network of potential gradient monitoring stations around a volcano can provide data on eruption time, magnitude, plume dispersion direction and areas of ashfall. Our laboratory experiments have produced electrically charged ash by fragmenting pumice. These results support the theory that charging is due to the magma fragmentation process and should therefore be ubiquitous in all particulate volcanic plumes.