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Magnetotelluric pulses generated by volcanic lightning at Sakurajima volcano, Japan
Author(s) -
Aizawa Koki,
Yokoo Akihiko,
Kanda Wataru,
Ogawa Yasuo,
Iguchi Masato
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2010gl044208
Subject(s) - volcano , geology , thunderstorm , lightning (connector) , seismology , magnetotellurics , vulcanian eruption , earth's magnetic field , geophysics , meteorology , physics , magnetic field , electrical resistivity and conductivity , oceanography , power (physics) , quantum mechanics
Continuous magnetotelluric (MT) measurements were conducted at Sakurajima volcano, Japan, revealing syn‐eruption electric pulses (and sometimes accompanying geomagnetic pulses). Movies of the eruptions, recorded with timing provided by a GPS clock, show a large number of volcanic lightning flashes. Some MT pulses occurred simultaneously with lightning flashes. Pulses were observed more than 10 seconds after the onset of the eruption, and tend to occur during eruptions that emit volcanic ash to high altitudes. Pulses were more common during mild eruptions rather than during Vulcanian eruptions. The observations suggest that the dominant mechanism of volcanic lighting is similar to that of lightning in thunderstorms, in that it requires the collision of particles and subsequent separation of positive and negative charge.