Στην διεύθυνση : http://www.sciencedirect.com/science/article/pii/S2214242814000047
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Το κείμενο είναι στα Αγγλικά, ενώ όπως αναφέρεται, στην
έρευνα συμμετείχαν η καθηγήτρια του τμήματος Γεωλογίας του Πανεπιστημίου της Αθήνας
Έυη Νομικού και ο Ιωσήφ Πέρρος από πλευράς του Πανεπιστημίου της Πελοποννήσου.
Σύμφωνα με το εισαγωγικό κείμενο της έρευνας,
The emergence
and growth of a submarine volcano: The Kameni islands, Santorini (Greece)
P. Nomikou,
Corresponding author contact information, E-mail the corresponding author, M.M.
Parksb, c, D. Papanikolaoua, D.M. Pyleb, T.A. Matherb, S. Careyd, A.B. Wattsb,
M. Paulattob, M.L. Kalninsb, I. Livanosa, K. Bejeloua, E. Simoua, I. Perros
The morphology
of a volcanic edifice reflects the integrated eruptive and evolutionary history
of that system, and can be used to reconstruct the time-series of prior
eruptions. We present a new high-resolution merged LiDAR-bathymetry grid, which
has enabled detailed mapping of both onshore and offshore historic lava flows
of the Kameni islands, emplaced in the centre of the Santorini caldera since at
least AD 46. We identify three new submarine lava flows: two flows, of unknown
age, lie to the east of Nea Kameni and a third submarine flow, located north of
Nea Kameni appears to predate the 1925–1928 lava flows but was emplaced
subsequent to the 1707–1711 lava flows. Yield strength estimates derived from
the morphology of the 1570/1573 lobe suggest that submarine lava strengths are
approximately two times greater than those derived from the onshore flows. To
our knowledge this is the first documented yield strength estimate for
submarine flows. This increase in strength is likely related to cooling and
thickening of the dacite lava flows as they displace sea water. Improved lava
volume estimates derived from the merged LiDAR-Bathymetry grid suggest typical
lava extrusion rates of ∼2–3 m3 s−1 during four of the historic eruptions on Nea Kameni (1707–1711,
1866–1870, 1925–1928 and 1939–1941). They also reveal a linear relationship
between the pre-eruption interval and the volume of extruded lava. These
observations may be used to estimate the size of future dome-building eruptions
at Santorini volcano, based on the time interval since the last significant
eruption.
Introduction
Analysis of lava
flow morphology can improve our understanding of historical effusive eruptions
by providing insights into the evolution of flow fields, lava effusion rates
and bulk rheological properties (e.g., [31], [14] and [5]). Lava flows are
considered non-Newtonian and are often modeled as Bingham fluids, which require
a critical shear stress (yield strength) to be exceeded to initiate viscous
flow [34] and [19]. Determination of rheological properties (e.g., yield
strength) provides insight into eruptive behaviour and the origin of flow
morphologies (e.g., [12], [38], [21], [30] and [3]). Morphological studies on
terrestrial volcanoes reveal strong positive correlations between, for example,
silica content and lava lobe width, which enables the estimation of lava flow
compositions on Earth, and elsewhere, by remote sensing (e.g., [41]).
