Magnetic Network on the Montagne Pelee Volcano (Martinique, Lesser Antilles) A Trial to Discriminate Volcanomagnetic Signal

Abstract

A significant area of abnormal conductivity, directed substantially SW-NE, can be found by studying the variations of the total intensity of the earth's magnetic field in the Montagne Pelée volcanic massif. The extremum of that abnormal effect occurs on the SW slopes of the volcano in the vicinity of the Morne Plumé. That result means an abnormally conductive feature that is probably to be related to the regional tectonics, directed SW-NE in the north of the Martinique island. The search for a possible volcanomagnetic effect that would accompany the activity of the volcano itself is conducted in such a way that the transient variations (“reduction defects”) encountered throughout the massif are taken into account. Through continuous computer recording of magnetic data, the transient variations over 24 hour long periods can be evaluated quite readily and a simple relationship can be proposed to account for a possible volcanomagnetic effect and the uncertainty about it. Thanks to the digital acquisition system, that effect can be assessed on a daily basis or at a higher rate. © 1986, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved.