Very long-period signals associated with Vulcanian Explosions at Popocatepetl Volcano, Mexico
Article first published online: 7 DEC 2012
Copyright 1999 by the American Geophysical Union.
Geophysical Research Letters
Volume 26, Issue 19, pages 3013–3016, 1 October 1999
How to Cite
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 26 AUG 1999
- Manuscript Received: 21 MAY 1999
Very long period (VLP) seismic signals associated with large summit eruptions of Popocatepetl volcano in the last four years are investigated using data from a broadband seismometer (0.04–120 s) deployed on the north flank of the volcano at a radial distance of 5 km from the active crater. The VLP signals associated with individual eruptions share similar waveforms. Discrete VLP signals accompanying long-period (LP) events also share similar signatures and have dominant periods that are nearly identical to those observed in the VLP waveforms of explosions. The VLP particle motions for eruption onsets consistently point to a source located a few km beneath the crater. The VLP ground displacement response to each explosion is marked by a compression, followed by a dilatation and terminating with another compression, suggesting a sequence of pressurization-depressurization-repressurization of the conduit. The repetitive nature of the waveforms points to a non-destructive source process which has remained active in the magmatic system of Popocatepetl at least since April 1997.