Detection of Ionospheric Perturbations Following an Earthquake with the Global Positioning System: Implications for Nuclear Tests Discrimination

Abstract

Sources such as undergroung nuclear explosions and strong shallow earthquakes causing large vertical near-field displacement of the earth’s surface are known to excite atmospheric acoustic and gravity waves that propagate upward in the atmosphere. At ionospheric altitudes these waves are coupled to ionospheric gravity waves and induce variations in the ionospheric electron density. In this work, we used Global Positioning System (GPS) data and identify such an ionospheric perturbation after the January 17, 1994, Northridge earthquake (California, USA). We show that the Global Positioning System (GPS) is a valuable tool for detecting ionospheric perturbations and therefore has the potential for contributing to nuclear test discrimination.