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Formation of rock coatings induced by the acid fumarole plume of the passively degassing volcano of La Fossa (Vulcano Island, Italy)
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Environmental impact of the acid fumarole plume of a passively degassing volcano (Vulcano Island, Italy)
No full textAbstract This paper investigates the
role played by the fumarolic plume
of a passive degassing volcano in the
genesis of rock coatings (RC) and in
the introduction and re-distribution
of metals and trace elements in the
surficial environment. At La Fossa
active volcano (Vulcano Island) and
in the surrounding environment RC
develop owing to exposure of the
ground surface to the volcanic acid
plume produced by the passive degassing
of La Fossa. Significant positive
anomalies of a wide variety of
metals and trace elements (including
Bi, Ag, Se, Te, Sb, Pb, As, Cu, Tl
and Cd) were observed either in
distal and proximal RC. Most of
these anomalies are interpreted to be
the result of the transport and subsequent
deposition of trace elements,
likely to form volatile compounds, in
the fumarolic plume. Two main
processes seem to control the geochemistry
of RC: one is represented
by the leaching and subsequent
deposition of elements from the
proximal toward the distal RC; the
other is the direct input of trace
elements carried by the emitted volcanic
aerosol. The fact that most of
the trace elements (particularly Pb,
As, Tl, Bi, Te, Se, Cd) enriched in
the RC of Vulcano are highly toxic
and potentially dangerous to health
in high concentration, indicates that
the atmospheric metal injection by
the quiescently degassing La Fossa
volcano together with the subsequent
deposition and remobilization
by means of surficial waters
may represent an environmental
hazard that should be taken into
account in evaluating the potential
impact of volcanic air pollution on
human health
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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