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Titel |
The ring-shaped thermal field of Stefanos crater, Nisyros Island: a conceptual model |
VerfasserIn |
M. Pantaleo, T. R. Walter |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1869-9510
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Digitales Dokument |
URL |
Erschienen |
In: Solid Earth ; 5, no. 1 ; Nr. 5, no. 1 (2014-04-01), S.183-198 |
Datensatznummer |
250115264
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Publikation (Nr.) |
copernicus.org/se-5-183-2014.pdf |
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Zusammenfassung |
Fumarole fields related to
hydrothermal processes release the heat of the underground through permeable
pathways. Thermal changes, therefore, are likely to depend also on the size
and permeability variation of these pathways. There may be different
explanations for the observed permeability changes, such as fault control,
lithology, weathering/alteration, heterogeneous sediment accumulation/erosion
and physical changes of the fluids (e.g., temperature and viscosity). A
common difficulty, however, in surface temperature field studies at active
volcanoes is that the parameters controlling the ascending routes of fluids
are poorly constrained in general. Here we analyze the crater of Stefanos,
Nisyros (Greece), and highlight complexities in the spatial pattern of the
fumarole field related to permeability conditions. We combine high-resolution
infrared mosaics and grain-size analysis of soils, aiming to elaborate
parameters controlling the appearance of the fumarole field. We find a
ring-shaped thermal field located within the explosion crater, which we
interpret to reflect near-surface contrasts of the soil granulometry and
volcanotectonic history at depth. We develop a conceptual model of how the
ring-shaped thermal field formed at the Stefanos crater and similarly at
other volcanic edifices, highlighting the importance of local permeability
contrast that may increase or decrease the thermal fluid flux. |
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