On the feasibility of magma fracture within volcanic conduits: Constraints from earthquake data and empirical modelling of magma viscosity

In the last decade several studies have indicated that magma within volcanic conduits can undergo repeated failure and healing, thus, providing a realistic source mechanism for the peculiar sequences of low‐frequency earthquakes that often announce eruptions. Although geological observations, labora...

Celý popis

Uložené v:

Podrobná bibliografia
Vydané v:	Geophysical research letters Ročník 38; číslo 19
Hlavní autori:	De Angelis, S., Henton, S. M.
Médium:	Journal Article
Jazyk:	English
Vydavateľské údaje:	Washington, DC Blackwell Publishing Ltd 01.10.2011 American Geophysical Union John Wiley & Sons, Inc
Predmet:	Conduits Earth sciences Earth, ocean, space Earthquakes Exact sciences and technology Failure Fracture mechanics Geology Geophysics Hills Magma magma viscosity Modelling Seismic activity Seismic phenomena Seismology shear fracture Viscosity Volcanic eruptions volcano seismology Volcanoes Central America Montserrat Soufriere Antilles America West Indies Lesser Antilles Saint Vincent Leeward Islands Caribbean region Laboratory study models andesites swarms volcanic rocks eruptions Geophysical observation igneous rocks case studies magmas earthquakes low frequency rupture viscosity depth hills Feasibility fractures sea level
ISSN:	0094-8276, 1944-8007
On-line prístup:	Získať plný text
Tagy:	Pridať tag Žiadne tagy, Buďte prvý, kto otaguje tento záznam!

Popis
Shrnutí:	In the last decade several studies have indicated that magma within volcanic conduits can undergo repeated failure and healing, thus, providing a realistic source mechanism for the peculiar sequences of low‐frequency earthquakes that often announce eruptions. Although geological observations, laboratory experiments, and numerical modelling support such a hypothesis, the links between geophysical observations and the proposed models remain qualitative. This study focuses on providing constraints to the relationship between the occurrence of repeating earthquakes and magma fracture at andesite volcanoes. Empirical modelling of viscosity is incorporated into the fundamental physics of magma fracture in order to assess whether and where the conditions for brittle failure are met within volcanic conduits. A case study from the 1995‐ongoing eruption of Soufrière Hills Volcano, Montserrat, is presented. The locations of earthquakes from a pre‐eruptive low‐frequency seismic swarm illuminate a relatively compact source volume at depths of 100–300 meters below sea level. Viscosity modelling confirms that the Soufrière Hills magma could rupture at those depths. Key Points Shear fracture of magma is feasible at shallow depth in volcanic conduits High magma crystallinity and/or elevated strain rates are necessary LF earthquake locations are compatible with magma fracture processes
Bibliografia:	istex:F7BB9D2F2B511AE26A45E3E340FB83FDDB5DE631 ark:/67375/WNG-4ZTRPQJC-0 ArticleID:2011GL049297 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 14 ObjectType-Article-1 ObjectType-Feature-2 content type line 23
ISSN:	0094-8276 1944-8007
DOI:	10.1029/2011GL049297