Publication Date:
2024-04-29
Description:
When a lava flow enters a body of water, either a lake, sea, river or ocean, explosive interaction may arise. However, when it is
an 'a'ā lava flow entering water, a more complex interaction occurs, that is very poorly described and documented in literature.
In this paper, we analysed the 2–4 ka San Bartolo lava flow field emplaced on the north flank of Stromboli volcano, Italy.
The lava flow field extends from ~ 650 m a.s.l. where the eruptive fissure is located, with two lava channels being apparent
on the steep down to the coast. Along the coast the lava flow field expands to form a lava delta ~ 1 km wide characterised
by 16 lava ‘Flow’ units. We performed a field survey to characterise the features of lava entering the sea and the associated
formation of different components and magnetic measurements to infer the flow fabrics and emplacement process of the lava
flow system. We measured the density, porosity and connectivity of several specimens to analyse the effect of lava-water
interaction on the content in vesicles and their connectivity and conducted a macroscopic componentry analysis (clast count)
at selected sites to infer the character of the eroded offshore segment of the lava flow field and its component flow units. The
collected data allowed us to define the main components of a lava delta fed by 'a'ā lava flows, with its channels, littoral units,
ramps, lava tubes, and inflated pāhoehoe flows controlled by the arterial 'a'ā flow fronts. The spatial organisation of these
components allowed us to build a three-step descriptive model for 'a'ā entering a water. The initial stage corresponds to the
entry of channel-fed 'a'ā lava flow into the sea which fragments to form metric blocks of 'a'ā lava. Continued lava supply to
the foreshore causes flow units to stall while spreading over this substrate. Subsequent 'a'ā lava flow units ramp up behind
the stalled flow front barrier. Lava tubes extending through the stalled flow barrier feed the seaward extension of a bench
made of several pāhoehoe flow units.
Description:
Open access funding provided by Università degli Studi di
Torino within the CRUI-CARE Agreement. This project is a part of
RS PhD project. This research was funded by MIUR ex-60% attributed
to EZ and PhD grants-Budget 10% attributed to RS. Also, it was
partially funded by the Project FIRST (ForecastIng eRuptive activity
at Stromboli volcano: Timing, eruptive style, size, intensity, and duration),
INGV-Progetto Strategico Dipartimento Vulcani 2019 (Delibera
n. 144/2020). This is contribution no. 637 of the ClerVolc program of
the International Research Center for Disaster Sciences and Sustainable
Development of the University of Clermont Auvergne.
Description:
Published
Description:
50
Description:
OSV1: Verso la previsione dei fenomeni vulcanici pericolosi
Description:
JCR Journal
Keywords:
Stromboli volcano
;
flank eruptions
;
Lava flows
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
