Great Sumatra Earthquake registers on electrostatic sensor



This article is corrected by:

  1. Errata: Corrections [to “Candidates for Office 2006–2008” biography for Alan Robock and “Great Sumatra Earthquake Registers on Electrosatic Sensor”] Volume 86, Issue 47, 486, Article first published online: 22 November 2005


Strong electrical signals that correspond to the Mw = 9.3 earthquake of 26 December 2004, whichoccurred at 0058:50.7 UTC off the west coast of northern Sumatra, Indonesia, were recorded by an electrostatic sensor (a device that detects short-term variations in Earth's electrostatic field) at a seismic station in Italy, which had been installed to study the influence of local earthquakes on a new landslide monitoring system.

Electrical signals arrived at the station practically instantaneously and were detected up to several hours before the onset of the Sumatra earthquake (Figure 1) as well as before local quakes. The corresponding seismic signals (p-waves) arrived 740 seconds after the start of the earthquake. Because the electrical signals travel at the speed of light, electrical monitoring for the global detection of very strong earthquakes could be an important tool in significantly increasing the hazard alert window.