Publication Date:
2017-04-04
Description:
Volcanic eruptions may create a wide range of risks in inhabited areas and, as a
consequence, major economic damage to the surrounding territory. An example of volcanic
hazard was given between 1998 and 2001 by Mt. Etna volcano, in Italy, with its frequent
paroxysmal explosive activity that caused more than a hundred fire-fountain episodes. In the
period January–June 2000, in particular, 64 lava fountains took place at the Southeast
Crater. During the most intense explosive phase of each episode, a sustained column often
formed, reaching up to 6 km above the eruptive vent. Then, the column started to expand
laterally causing more or less copious tephra fallout on the slopes of Etna; ash and lapilli,
therefore, constituted a serious danger for vehicular and air traffic. A software and hardware
warning system was developed to mitigate the volcanic hazard indicating the areas affected
by potential ash and lapilli fallout. The alert system was mainly based on the good correspondence
between the pattern of volcanic tremor amplitude and the evolution of explosive
activity. When a fixed tremor threshold was exceeded, a semiautomatic process started to
send faxes to Civil Defence and Municipalities directly affected by tephra fallout, together
with information on wind directions from the Meteorological Office. The application of this
methodology, during the last 14 eruptive episodes in 2000 and the 14 events occurred in
2001, demonstrated the good correspondence between the forecasts on the areas affected by
tephra fallout and the effective tephra distribution on land. Despite the integrity of the
performance provided by the alert system, small discrepancies occurred in the technical
procedure of alerting, for which possible solutions have been discussed. The improvement
of this type of system, could become basic for the Etnean region and be proposed for similar
volcanic areas throughout the world.
Description:
Published
Description:
333-350
Description:
1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
Description:
1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
Description:
JCR Journal
Description:
reserved
Keywords:
Alert system
;
Volcanic surveillance
;
Volcanic tremor
;
Lava fountain
;
Tephra fallout
;
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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