Publication Date:
2017-04-04
Description:
One of the main issues in seismic monitoring of active volcanic areas is the
accurate location of earthquake hypocenters. Volcano-tectonic seismicity is
often characterized by small magnitude swarms, recorded by few seismic stations
with a high picking uncertainty. Sometimes events lacks clear S-wave arrivals,
due to the nature of some volcanic sources. All these features, together
with the complex crustal structure of volcanoes, makes the earthquake location
problem critical in such areas.
One of the most important effort for improving the quality of hypocenter
location is the use of realistic 3D velocity models. In the last 10 years, several
scientific papers proposed 2D and 3D velocity models for Mt. Vesuvius,
Campi Flegrei and the Gulf of Naples. They comes from both active seismic
data (VESUVIO 94, TOMOVES 96, MAREVES 97 and SERAPIS 2001
experiments) and from local earthquake tomography.
In this report we propose a global unified velocity model spanning from Ischia
island to Appennine Mts. that allows us to locate earthquakes in the
Neapolitan volcanic areas and in the Gulf of Naples. This model comes from
a weighted averaging of 5 tomographic velocity models and a background
regional model. Most of the model provides only P-wave velocities, only 2
models, obtained through local earthquake tomography at Mt. Vesuvius and
Campi Flegrei also gives a S-wave velocity estimate.
We show the difference between this new model and the previous 1D models
adopted for routine locations at INGV-Osservatorio Vesuviano. We also relocate
some events, using non-linear techniques showing differences in hypocenter
position from previous locations and the improvement in final traveltime
residuals and location uncertainties.
Description:
Published
Description:
375-390
Description:
1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
Description:
open
Keywords:
Volcano-tectonic seismicity
;
3D velocity model
;
04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
book chapter
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