Transient conduit permeability controlled by a shift between compactant shear and dilatant rupture at Unzen volcano (Japan)

Abstract ∼ ∼ ∼ ∼  500 m depth. At this point the compactional shear zone would have been locally overprinted by brittle rupture, promoting the development of a shear fault and dilational Riedel fractures during repeating phases of increased magma ascent rate, enhancing anisotropic permeability that channels fluid flow into and along the conduit margin. In contrast, we interpret the central shear zone as a shallow, late-stage dilational structure, which partially tore the core of the spine, leaving a slight permanent displacement. We explore constraints from monitored seismicity and stick-slip behaviour to evaluate the rheological controls, which accompanied the shift from compactional toward dilational shear as magma approached the surface, and discuss their importance in controlling the permeability development of magma evolving from overall ductile to increasingly brittle behaviour during ascent and eruption.

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch

References and Relationships

• Bibliographic citation: Transient conduit permeability controlled by a shift between compactant shear and dilatant rupture at Unzen volcano (Japan) ; volume:13 ; number:5 ; year:2022 ; pages:875-900 ; extent:26 ; Solid earth ; 13, Heft 5 (2022), 875-900 (gesamt 26)

Contributors, Places and Time

• Creator: Lavallée, Yan ; Miwa, Takahiro ; Ashworth, James D. ; Wallace, Paul A. ; Kendrick, Jackie E. ; Coats, Rebecca ; Lamur, Anthony ; Hornby, Adrian ; Hess, Kai-Uwe ; Matsushima, Takeshi ; Nakada, Setsuya ; Shimizu, Hiroshi ; Ruthensteiner, Bernhard ; Tuffen, Hugh

Further information

• DOI: 10.5194/se-13-875-2022
• URN: urn:nbn:de:101:1-2022051205143618999549
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 15.08.2025, 7:34 AM CEST