M.J.S. Johnston
2002
<p><span>Independent knowledge of the physical processes that occur with seismic events can be obtained from observations of electric and magnetic fields generated by these complex processes. During the past few decades, we have seen a remarkable increase in the quality and quantity of electromagnetic (EM) data recorded before and during earthquakes and volcanic eruptions. This paper describes the most significant recent data and the implications these data have for different generating mechanisms. We note that, despite several decades of relatively high quality monitoring, clear demonstration of the existence of precursory EM signals has not been achieved, although causal relations between coseismic magnetic field changes and earthquake stress drops are no longer in question. This paper extends discussions of tectonomagnetism and tectonoelectricity, over the various parts of the electromagnetic spectrum from radio frequencies (RF) to submicrohertz frequencies, that are covered in Johnston (1989, 1997), Park </span><i>et al.</i><span> (1993), </span><span class="anchor-text">Park (1996)</span><span> special journal issues (</span><span class="anchor-text">Johnston and Parrot, 1989</span><span>, 1998; </span><span class="anchor-text">Parrot and Johnston, 1993</span><span>), and books (</span><span class="anchor-text">Hayakawa and Fujinawa, 1994</span><span>).</span></p>
application/pdf
10.1016/S0074-6142(02)80241-8
en
Elsevier
38 - Electromagnetic fields generated by earthquakes
article