Nested zones of instability in the Mount Etna volcanic edifice, Italy
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| Title: | Nested zones of instability in the Mount Etna volcanic edifice, Italy |
|---|---|
| Authors: | Rust, D.1 derek.rust@brunel.ac.uk, Behncke, B.2 behncke@unict.it, Neri, M.2 neri@ct.ingv.it, Ciocanel, A.1 |
| Source: | Journal of Volcanology & Geothermal Research. Jun2005, Vol. 144 Issue 1-4, p137-153. 17p. |
| Subjects: | Volcanism, Volcanoes |
| Geographic Terms: | Mount Etna (Italy), Italy |
| Abstract: | Abstract: Large-scale flank instability on Mount Etna is associated with a distinct set of faults radiating generally from the summit area and restricted to the volcanic edifice itself. New observations and mapping of very recent and continuing deformation along these faults and related structures have been analysed in combination with published information, including recent seismic and eruption data, enabling the faults to be placed in three groups. Two of these, the Pernicana fault system (PFS) and the Ragalna fault system (RFS) bound, respectively, the northern and south-western margins of instability. Their activity responds to cycles of magma pressure associated with flank eruptions, together with subsequent deflation as gravity dominates. These cycles may operate at different depths, with the RFS bordering deep-seated instability. Their positions appear governed by the contact, in the substrate of the volcano, between relatively weak early Quaternary clays and stronger rocks of the Apennine–Maghrebian Chain that rise towards the north and west in the subsurface, buttressing the edifice in these directions. The unstable mass to the un-buttressed south and east is thus defined by its weak substrate and displays structures similar to those produced in model experiments. The third fault group, the Mascaluci–-Trecastagni fault system, borders a rather faster-moving zone of instability in the eastern part of the large unstable mass, outlining one element in a nested pattern in map view. Low-angle detachments below the unstable zones are thought to occur at different levels above a deep and laterally extensive detachment associated with the RFS, producing a nested pattern in section as well. This is illustrated by the PFS where the long-recognised western half of the fault borders a fast moving zone of instability riding above a detachment that daylights as a thrusted deformation front marked by recurring landsliding at an approximate mid-slope position on the volcano. Downslope, the newly recognised eastern extension of the PFS, exhibiting slip-rates an-order-of-magnitude lower than the western segment, is thought to border a deeper slow-moving detachment that daylights offshore. Windows of deformed sub-Etnean clays at anomalously high altitudes may indicate where similar detachments, no longer mechanically favoured and now inactive, have daylighted. As a result, the edifice can be considered, overall, as consisting of multiple unstable areas, nested in plan view and with basal detachments occurring at different levels in section. This model of edifice behaviour is regarded as an evolving one, with detachments waxing and waning in their activity as flank movement progresses. [Copyright &y& Elsevier] |
| Copyright of Journal of Volcanology & Geothermal Research is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 18093081 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Nested zones of instability in the Mount Etna volcanic edifice, Italy – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Rust%2C+D%2E%22">Rust, D.</searchLink><relatesTo>1</relatesTo><i> derek.rust@brunel.ac.uk</i><br /><searchLink fieldCode="AR" term="%22Behncke%2C+B%2E%22">Behncke, B.</searchLink><relatesTo>2</relatesTo><i> behncke@unict.it</i><br /><searchLink fieldCode="AR" term="%22Neri%2C+M%2E%22">Neri, M.</searchLink><relatesTo>2</relatesTo><i> neri@ct.ingv.it</i><br /><searchLink fieldCode="AR" term="%22Ciocanel%2C+A%2E%22">Ciocanel, A.</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Volcanology+%26+Geothermal+Research%22">Journal of Volcanology & Geothermal Research</searchLink>. Jun2005, Vol. 144 Issue 1-4, p137-153. 17p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Volcanism%22">Volcanism</searchLink><br /><searchLink fieldCode="DE" term="%22Volcanoes%22">Volcanoes</searchLink> – Name: SubjectGeographic Label: Geographic Terms Group: Su Data: <searchLink fieldCode="DE" term="%22Mount+Etna+%28Italy%29%22">Mount Etna (Italy)</searchLink><br /><searchLink fieldCode="DE" term="%22Italy%22">Italy</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Abstract: Large-scale flank instability on Mount Etna is associated with a distinct set of faults radiating generally from the summit area and restricted to the volcanic edifice itself. New observations and mapping of very recent and continuing deformation along these faults and related structures have been analysed in combination with published information, including recent seismic and eruption data, enabling the faults to be placed in three groups. Two of these, the Pernicana fault system (PFS) and the Ragalna fault system (RFS) bound, respectively, the northern and south-western margins of instability. Their activity responds to cycles of magma pressure associated with flank eruptions, together with subsequent deflation as gravity dominates. These cycles may operate at different depths, with the RFS bordering deep-seated instability. Their positions appear governed by the contact, in the substrate of the volcano, between relatively weak early Quaternary clays and stronger rocks of the Apennine–Maghrebian Chain that rise towards the north and west in the subsurface, buttressing the edifice in these directions. The unstable mass to the un-buttressed south and east is thus defined by its weak substrate and displays structures similar to those produced in model experiments. The third fault group, the Mascaluci–-Trecastagni fault system, borders a rather faster-moving zone of instability in the eastern part of the large unstable mass, outlining one element in a nested pattern in map view. Low-angle detachments below the unstable zones are thought to occur at different levels above a deep and laterally extensive detachment associated with the RFS, producing a nested pattern in section as well. This is illustrated by the PFS where the long-recognised western half of the fault borders a fast moving zone of instability riding above a detachment that daylights as a thrusted deformation front marked by recurring landsliding at an approximate mid-slope position on the volcano. Downslope, the newly recognised eastern extension of the PFS, exhibiting slip-rates an-order-of-magnitude lower than the western segment, is thought to border a deeper slow-moving detachment that daylights offshore. Windows of deformed sub-Etnean clays at anomalously high altitudes may indicate where similar detachments, no longer mechanically favoured and now inactive, have daylighted. As a result, the edifice can be considered, overall, as consisting of multiple unstable areas, nested in plan view and with basal detachments occurring at different levels in section. This model of edifice behaviour is regarded as an evolving one, with detachments waxing and waning in their activity as flank movement progresses. [Copyright &y& Elsevier] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Volcanology & Geothermal Research is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.jvolgeores.2004.11.021 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 17 StartPage: 137 Subjects: – SubjectFull: Volcanism Type: general – SubjectFull: Volcanoes Type: general – SubjectFull: Mount Etna (Italy) Type: general – SubjectFull: Italy Type: general Titles: – TitleFull: Nested zones of instability in the Mount Etna volcanic edifice, Italy Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Rust, D. – PersonEntity: Name: NameFull: Behncke, B. – PersonEntity: Name: NameFull: Neri, M. – PersonEntity: Name: NameFull: Ciocanel, A. IsPartOfRelationships: – BibEntity: Dates: – D: 15 M: 06 Text: Jun2005 Type: published Y: 2005 Identifiers: – Type: issn-print Value: 03770273 Numbering: – Type: volume Value: 144 – Type: issue Value: 1-4 Titles: – TitleFull: Journal of Volcanology & Geothermal Research Type: main |
| ResultId | 1 |
