期刊名称:IOP Conference Series: Earth and Environmental Science
印刷版ISSN:1755-1307
电子版ISSN:1755-1315
出版年度:2008
卷号:3
出版社:IOP Publishing
摘要:Plan-view ellipticity of a pre-caldera magma reservoir, and its influence on the
development of caldera ring fracturing and eruptive behaviour, have not
previously been subjected to dedicated evaluation. We experimentally simulated
caldera collapse into elliptical magma chambers and found that collapse into
highly-elliptical chambers produced a characteristic pattern of ring-fault
localization and lateral propagation. Although results are preliminary, the
general deformation pattern for elliptical resurgence shows strong similarities
to elliptical collapse. Ring faults accommodating uplift again initiate around
the chamberõs short axis and are reverse, but dip inward. Field and geophysical
observations at several elliptical calderas of varying scale (e.g. Long Valley,
Katmai, and Rabaul calderas) are consistent with a control from elliptical magma
chamber geometry on ring fracturing and eruption, as predicted from our
experiments.
关键词:caldera, elliptical, subsidence, resurgence, ring fractures, volcanic eruptions