Publication Date:
2017-04-04
Description:
Between 1971 and 2001, the Southeast Crater
was the most productive of the four summit craters of
Mount Etna, with activity that can be compared, on a global
scale, to the opening phases of the Pu‘u ‘Ō‘ō-Kūpaianaha
eruption of Kīlauea volcano, Hawai‘i. The period of
highest eruptive rate was between 1996 and 2001, when
near-continuous activity occurred in five phases. These
were characterized by a wide range of eruptive styles and
intensities from quiet, non-explosive lava emission to brief,
violent lava-fountaining episodes. Much of the cone
growth occurred during these fountaining episodes, totaling
105 events. Many showed complex dynamics such as
different eruptive styles at multiple vents, and resulted in
the growth of minor edifices on the flanks of the Southeast
Crater cone. Small pyroclastic flows were produced during
some of the eruptive episodes, when oblique tephra jets
showered the steep flanks of the cone with hot bombs and
scoriae. Fluctuations in the eruptive style and eruption rates
were controlled by a complex interplay between changes in
the conduit geometry (including the growth of a shallow
magma reservoir under the Southeast Crater), magma
supply rates, and flank instability. During this period,
volume calculations were made with the aid of GIS and
image analysis of video footage obtained by a monitoring
telecamera. Between 1996 and 2001, the bulk volume of
the cone increased by ~36×106 m3, giving a total (1971–
2001) volume of ~72×106 m3. At the same time, the cone
gained ~105 m in height, reaching an elevation of about
3,300 m. The total DRE volume of the 1996–2001 products was ~90×106m3. This mostly comprised lava flows
(72×106 m3) erupted at the summit and onto the flanks of
the cone. These values indicate that the productivity of the
Southeast Crater increased fourfold during 1996–2001
with respect to the previous 25 years, coinciding with a
general increase in the eruptive output rates and eruption
intensity at Etna. This phase of intense summit activity has
been followed, since the summer of 2001, by a period of
increased structural instability of the volcano, marked by a
series of important flank eruptions.
Description:
Published
Description:
149-173
Description:
reserved
Keywords:
Mount Etna
;
Lava fountaining
;
Microplinian
;
Remote video monitoring
;
Volume calculations
;
Cone growth
;
04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Format:
1912898 bytes
Format:
application/pdf
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