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Magma‐driven subcritical crack growth and implications for dike initiation from a magma chamber
Author(s) -
Chen Zuan,
Jin Z.H.
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl026979
Subject(s) - dike , magma chamber , geology , viscoelasticity , magma , dissipation , buoyancy , fracture mechanics , stress intensity factor , mechanics , petrology , materials science , seismology , thermodynamics , volcano , composite material , physics
The purpose of this paper is to explore a viscoelastic energy dissipation theory for subcritical dike growth from a magma chamber. The theoretical relationship between the dike growth velocity and dike length is established using the viscoelastic subcritical crack growth theory proposed by the first author and the solutions of stress intensity factor at the crack tip derived by a perturbation method. Effects of magma chamber over‐pressure, buoyancy and viscoelastic properties of the host rock on the subcritical growth rate are included in the model. The numerical results indicate that the viscous energy dissipation of the host rock could allow a short dike to slowly grow on the order of 10 −7 –10 −5 m/s under modest over‐pressure and to accelerate when the stress intensity factor increases close to the fracture toughness, followed by the unstable dike propagation. The proposed theory provides a reasonable understanding of dike initiation process from a magma chamber.