応力場と火山噴火

抄録

Useful expressions are collected and discussed for deformations due to (1) various types of magmatic pressure sources and (2) surface loading over a circular area. Subsequently (3) the stress concentration around spherical and cylindrical cavities in an infinite elastic medium is reviewed, providing a correlation between the regional stress field and the stress on the wall of the magma chamber and conduit. Taking three cases of Japanese active volcanoes, it is suggested that studies in mechanical state of the magmatic pressure sources and failure criteria of the surrounding rocks may be helpful to estimate long and intermediate-term potentials of large volcanic eruptions.