Publication Date:
2017-04-04
Description:
We investigate the ability of GPS to detect
volcanic plumes at Mt. Etna, Italy. We use a robust statistical
approach to highlight whether the presence of a
volcanic plume in the atmosphere may really affect the
GPS undifferenced post-fit phase residuals. The proposed
method has been tested for the September 4–5, 2007
activity of Mt. Etna. This eruption produced powerful lava
fountains forming a weak, a few kilometers high plume for
several hours, representing typical activity at Etna over the
last 5 years. We analyzed data from nineteen Etna permanent
GPS stations located on the volcano flanks at different
heights and applied a statistical test based on four
main steps: (a) realization of a simplified model representing
the volcanic plume in atmosphere; (b) evaluation of
the GPS satellite and station couples intersecting the
plume; (c) calculation of the volcanic plume region crossed
by the GPS signal; (d) application of a robust statistical test
in order to see whether the volcanic plume affected the
GPS signals. Results show that during the September 4–5,
2007 explosive activity, the GPS residuals definitely
include the contribution of the volcanic plume. Our analysis
shows that values of the GPS residuals are ten times
smaller than those found for the Miyakejima eruption
(Japan), highlighting a likely relationship between residuals
and eruption intensity. In the future, data derived from
the GPS stations located on Etna’s flanks could be used to
improve the alerting system of volcanic ash, already
operating at the Istituto Nazionale di Geofisica e Vulcanologia,
Osservatorio Etneo.
Description:
Published
Description:
485-497
Description:
1.7. Osservazioni di alta e media atmosfera
Description:
JCR Journal
Description:
restricted
Keywords:
GPS
;
volcanic ash
;
01. Atmosphere::01.01. Atmosphere::01.01.08. Instruments and techniques
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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