Magnetic precursors to the 2013 eruptive activity at Popocatepetl Volcano, Mexico
Abstract
Popocateptl volcano, 60km from Mexico City, has been erupting since 1994 with periods of more intense activity. Volcanomagnetic signals at Popocatepetl have been correlated with different volcanic phenomena especially ascent of several magma batches in pulses lasting several hours that precede increasing seismicity at the volcano. Data from the TL magnetic station on the northern flank of the volcano at 4000masl and from the CPX station at the same altitude on the southwestern flank are processed with the data from the TEO base station (weighted differences) in order to remove signals not associated with the volcano. Short term negative volcanic anomalies around 10nT preceded sharp increases in seismicity and copious ash emission during April and May 2013. They were correlated with periods of harmonic tremor and interpreted as new ascending magma batches, below the Curie point. A longer term descending magnetic trend from February on, is of thermomagnetic origen and is associated with the more mafic andesite compositions of the ash which contain higher MgO and are consistent with influx of deeper magma at higher magmatic temperatures. Sharp positive magnetic peaks are related both with explosions and seismic events, while sustained steps of positive anomalies are related with dome growth and cooling
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.V13E2665M
- Keywords:
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- 8414 VOLCANOLOGY Eruption mechanisms and flow emplacement;
- 8419 VOLCANOLOGY Volcano monitoring;
- 8434 VOLCANOLOGY Magma migration and fragmentation;
- 0925 EXPLORATION GEOPHYSICS Magnetic and electrical methods