Publication Date:
2017-04-04
Description:
Volcano monitoring aims at the recognition of changes in instrumentally observable parameters before
hazardous activity in order to alert governmental authorities. Among these parameters seismic data in general
and volcanic tremor in particular play a key role. Recent major explosive eruptions such as Okmok (Aleutians)
and Chaitén (Chile) in 2008 and numerous smaller events at Mt Etna (Italy), have shown that the period of
premonitory seismic activity can be short (only a few hours), which entails the necessity of effective
automatic data processing near on-line. Here we present a synoptic pattern classification analysis based on
Self Organizing Maps and Fuzzy Cluster Analysis which is applied to volcanic tremor data recorded during a
series of paroxysmal eruptive episodes and a flank eruption at Etna in 2007–2008. In total, eight episodes
were analyzed; in six of these significant changes in the dynamic regime of the volcano were detected up to
9 h prior to the onset of eruptive activity, and long before changes in volcanic tremor amplitude and spectral
content became evident in classical analysis. In two cases, the state transition was b1 h before the onset of
eruptive activity, which we interpret as evidence for very rapid magma ascent through an open conduit. We
further detected twenty failed paroxysms, that is episodes of volcanic unrest that did not culminate in
eruptive activity, between March and April 2007. As the application of the software for this synoptic pattern
classification is straightforward and requires only moderate computational resources, it was possible to
exploit it in an on-line application, which was tested and now is in use at the Istituto Nazionale di Geofisica e
Vulcanologia in Catania for the monitoring of Etna. We believe that the pattern classification presented here
may become a powerful addition to the repertoire of volcano monitoring tools and early warning techniques
worldwide.
Description:
Published
Description:
1-17
Description:
1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
Description:
JCR Journal
Description:
restricted
Keywords:
volcanic tremor, volcano monitoring, pattern recognition, Self Organizing Maps. fuzzy clustering, Mt Etna
;
01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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