The Open UniversitySkip to content
 

The cryptic summit graben of Mt. Etna volcano

Murray, John B. (2019). The cryptic summit graben of Mt. Etna volcano. Journal of Volcanology and Geothermal Research, 387, article no. 106657.

Full text available as:
[img]
Preview
PDF (Version of Record) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (4MB) | Preview
DOI (Digital Object Identifier) Link: https://doi.org/10.1016/j.jvolgeores.2019.07.024
Google Scholar: Look up in Google Scholar

Abstract

Previous studies have inferred the likelihood of a summit graben at Mt. Etna, but until now there has been no direct observation or evidence of such a feature. Here, the results of 43 years of deformation measurements at the summit are reported, in which the presence of an actively forming north-south graben 1.5 km wide is evident, with a maximum subsidence of nearly 4 m in 43 years. Its bounding faults have in most places been hidden by the eruptive deposits of 190 summit eruptions, but horizontal measurements across these faults show a maximum value of nearly 9 m of east-west extension. Most of the subsidence and extension has taken place during the injection of eruption feeder dykes, with extreme values for single events of −1.7 m subsidence during the injection of the 2002–2003 dyke, and 4.4 m extension across the 1989 feeder dyke, but subsidence and extension continues to take place slowly during inter-eruptive periods. Analogue modelling indicates that its origin is probably a consequence of the gravitational spreading and downslope sliding of the Etna edifice on its clay-rich substrate, aided by magmatic pressure from feeder dykes intruded into individual faults, and by downward pressure from surface loading of erupted lava. This study clarifies the way in which the mechanism of gravitational spreading is maintained throughout the lifetime of this and other spreading volcanoes and rifts on Earth and Mars.

Item Type: Journal Item
Copyright Holders: 2019 Elsevier
ISSN: 0377-0273
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Environment, Earth and Ecosystem Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Item ID: 66177
Depositing User: ORO Import
Date Deposited: 12 Aug 2019 13:31
Last Modified: 25 Jan 2020 17:07
URI: http://oro.open.ac.uk/id/eprint/66177
Share this page:

Metrics

Altmetrics from Altmetric

Citations from Dimensions

Download history for this item

These details should be considered as only a guide to the number of downloads performed manually. Algorithmic methods have been applied in an attempt to remove automated downloads from the displayed statistics but no guarantee can be made as to the accuracy of the figures.

Actions (login may be required)

Policies | Disclaimer

© The Open University   contact the OU