Conditions of atmospheric electricity variation during seismic wave propagation

This study reports the observation of co-seismic electromagnetic phenomena, including earth potential difference (EPD) variation and atmospheric electricity (AE) variation, at three observation sites in Akita Prefecture. During the strong earthquake of 2 December, we observed clear signals of EPD and AE variation at all three sites. However, the amplitudes of both observed signals at those three sites differ greatly, but have almost equal quake intensity at each site. The AE signal's amplitude increases along with the increase in amplitude of the EPD signal at every site. A model describing the appearance of both variation signals is proposed to explain the observed data. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(3): 1–9, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20230 Copyright © 2006 Wiley Periodicals, Inc.