Publication Date:
2017-04-04
Description:
The spatial pattern of the b value of the frequency-magnitude relation has been
analyzed using gridding techniques beneath Mount Etna, Italy. A regional data set of
2900 events with Md (duration magnitude) 1.5 up to 15 km depth occurring between August 1999 and December 2005 has been used. Two regions with an abnormally high b value have been found, one centered beneath the southern part of the Valle del Bove, above the 6 km below sea level (bsl) deep basement, and the other beneath the summit region 2 km bsl east of the Central Craters. We can infer that these high b value anomalies are regions of increased crack density, and/or high pore pressure, related to the presence of nearby magma storage. This interpretation is supported by all the available geophysical
evidence, such as tomographic studies and geodetic deformation measurements. The data set has also been subdivided into five periods, corresponding to different phases of
volcanic activity: 2001 preeruption, 2001 eruptive, 2002–2003 preeruption, 2002–2003
eruptive, and 2002–2003 posteruption. The minimum magnitude of completeness, Mc, and the b value were computed for each period. A volume of anomalously high b values can be observed in each of these periods (except for the 2002–2003 preeruption interval). This approach has allowed the detection of the transient presence of magmatic intrusions during the various periods evaluated.
Description:
Published
Description:
B12303
Description:
1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
Description:
4.3. TTC - Scenari di pericolosità vulcanica
Description:
JCR Journal
Description:
reserved
Keywords:
b value
;
Mount Etna
;
frequency-magnitude relation
;
magmatic intrusions
;
04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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