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Logarithmic Growth of Dikes From a Depressurizing Magma Chamber
Author(s) -
GrossmanPonemon Benjamin E.,
Heimisson Elías R.,
Lew Adrian J.,
Segall Paul
Publication year - 2020
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 - 10.1029/2019gl086230
Subject(s) - dike , geology , cabin pressurization , magma , magma chamber , flow (mathematics) , mechanics , deformation (meteorology) , fracture (geology) , fluid dynamics , geotechnical engineering , seismology , petrology , volcano , materials science , physics , oceanography , composite material
Dike propagation is an intrinsically multiphase problem, where deformation and fluid flow are intricately coupled in a fracture process. Here we perform the first fully coupled simulations of dike propagation in two dimensions, accounting for depressurization of a circular magma chamber, dynamic fluid flow, fracture formation, and elastic deformation. Despite the complexity of the governing equations, we observe that the lengthening is well explained by a simple model a ( t ) = c 1 log ( 1 + t / c 2 ) , where a is the dike length, t is time, andc 1andc 2are constants. We compare the model to seismic data from eight dikes in Iceland and Ethiopia, and, in spite of the assumption of plane strain, we find good agreement between the data and the model. In addition, we derive an approximate model for the depressurization of the chamber with the dike length. These models may help forecast the growth of lateral dikes and magma chamber depressurization.