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| Titel |
Forecasting eruptions after long repose intervals from accelerating rates of rock fracture: The June 1991 eruption of Mount Pinatubo, Philippines |
| VerfasserIn |
Rosanna Smith, Christopher Kilburn |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250036142
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| Zusammenfassung |
| Mount Pinatubo, Philippines erupted on 7th June 1991, after 500 years of repose and two
months of detected seismic unrest. Accelerating volcano tectonic (VT) earthquake rates in the
final days before this eruption have previously been used to develop eruption forecasting
models based on extension and coalescence of fractures in the volcanic edifice forming a
new pathway for magma ascent to the surface. We have re-analysed the precursory
acceleration in VT earthquake rates using these forecasting models, in order to
test their accuracy and sensitivity to how the VT earthquake data are gathered.
Binning the data into fixed VT number intervals rather than fixed time intervals gave
more precise forecasts. The eruption occurred 24 hours after the forecast time,
and the interval was characterised by a sustained high rate of VT seismicity. We
suggest that the difference between the forecast and actual eruption times reflects
a real time lag due to the conditions of magma ascent. In this case, the forecast
time is associated with completion of a new conduit, whereas the high rate of VT
seismicity in the following 24 hours is attributed to the widening of the conduit and
to friction between magma and country rock as the magma rose to the surface. |
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