Seismomagnetic observation during the 8 July 1986 magnitude 5.9 North Palm Springs earthquake
A differentially connected array of 24 proton magnetometers has operated along the San Andreas fault since 1976. Seismomagnetic offsets of 1.2 and 0.3 nanotesla were observed at epicentral distances of 3 and 9 kilometers, respectively, after the 8 July 1986 magnitude 5.9 North Palm Springs earthquake. These seismomagnetic observations are the first obtained of this elusive but long-anticipated effect. The data are consistent with a seismomagnetic model of the earthquake for which right-lateral rupture of 20 centimeters is assumed on a 16-kilometer segment of the Banning fault between the depths of 3 and 10 kilometers in a region with average magnetization of 1 ampere per meter. Alternative explanations in terms of electrokinetic effects and earthquake-generated electrostatic charge redistribution seem unlikely because the changes are permanent and complete within a 20-minute period.
Citation Information
Publication Year | 1987 |
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Title | Seismomagnetic observation during the 8 July 1986 magnitude 5.9 North Palm Springs earthquake |
Authors | M.J.S. Johnston, R.J. Mueller |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Science |
Index ID | 70014214 |
Record Source | USGS Publications Warehouse |