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The Hengill geothermal area, Iceland: variation of temperature gradients deduced from the maximum depth of seismogenesis

Journal of Volcanology and Geothermal Research

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DOI: 10.1016/0377-0273(94)00088-X

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Abstract

Given a uniform lithology and strain rate and a full seismic data set, the maximum depth of earthquakes may be viewed to a first order as an isotherm. These conditions are approached at the Hengill geothermal area, S. Iceland, a dominantly basaltic area. The temperature at which seismic failure ceases for the strain rates likely at the Hengill geothermal area is determined by analogy with oceanic crust, and is about 650 ?? 50??C. The topographies of the top and bottom of the seismogenic layer were mapped using 617 earthquakes. The thickness of the seismogenic layer is roughly constant and about 3 km. A shallow, aseismic, low-velocity volume within the spreading plate boundary that crosses the area occurs above the top of the seismogenic layer and is interpreted as an isolated body of partial melt. The base of the seismogenic layer has a maximum depth of about 6.5 km beneath the spreading axis and deepens to about 7 km beneath a transform zone in the south of the area. -from Author

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
The Hengill geothermal area, Iceland: variation of temperature gradients deduced from the maximum depth of seismogenesis
Series title:
Journal of Volcanology and Geothermal Research
DOI:
10.1016/0377-0273(94)00088-X
Volume
65
Issue:
1-2
Year Published:
1995
Language:
English
Publisher:
Elsevier
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Volcanology and Geothermal Research
First page:
119
Last page:
133