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Propagation of the Hawaiian-Emperor volcano chain by Pacific plate cooling stress

Special Paper of the Geological Society of America

By:
, , and
DOI: 10.1130/2007.2430(24)

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Abstract

The lithosphere crack model, the main alternative to the mantle plume model for age-progressive magma emplacement along the Hawaiian-Emperor volcano chain, requires the maximum horizontal tensile stress to be normal to the volcano chain. However, published stress fields calculated from Pacific lithosphere tractions and body forces (e.g., subduction pull, basal drag, lithosphere density) are not optimal for southeast propagation of a stress-free, vertical tensile crack coincident with the Hawaiian segment of the Hawaiian-Emperor chain. Here we calculate the thermoelastic stress rate for present-day cooling of the Pacific plate using a spherical shell finite element representation of the plate geometry. We use observed seafloor isochrons and a standard model for lithosphere cooling to specify the time dependence of vertical temperature profiles. The calculated stress rate multiplied by a time increment (e.g., 1 m.y.) then gives a thermoelastic stress increment for the evolving Pacific plate. Near the Hawaiian chain position, the calculated stress increment in the lower part of the shell is tensional, with maximum tension normal to the chain direction. Near the projection of the chain trend to the southeast beyond Hawaii, the stress increment is compressive. This incremental stress field has the form necessary to maintain and propagate a tensile crack or similar lithosphere flaw and is thus consistent with the crack model for the Hawaiian volcano chain.?? 2007 The Geological Society of America.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Propagation of the Hawaiian-Emperor volcano chain by Pacific plate cooling stress
Series title:
Special Paper of the Geological Society of America
DOI:
10.1130/2007.2430(24)
Issue:
430
Year Published:
2007
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Special Paper of the Geological Society of America
First page:
497
Last page:
506