Thermal diffusivity of MORB-composition rocks to 15 GPa: implications for triggering of deep seismicity

David P Dobson; Simon A Hunt; Richard McCormack; Oliver T Lord; Weidner Donald J.; Li Li; Andrew M Walker

doi:10.1080/08957959.2010.516827

Thermal diffusivity of MORB-composition rocks to 15 GPa: implications for triggering of deep seismicity

David P Dobson, Simon A Hunt, Richard McCormack, Oliver T Lord, Weidner Donald J., Li Li, Andrew M Walker

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Abstract

We have measured the thermal diffusivity of eclogite and majorite with a model MORB composition at pressures of 3 and 15 GPa, respectively. Both phase assemblages show inverse dependences of their thermal diffusivities on temperature: D _eclogite=9(10)×10⁻¹⁰+7(1)×10⁻⁴/T(K) m ²/s and D _majorite=6.2(5)×10⁻⁷+3.0(5)×10⁻⁴/T(K) m ²/s. The values for majorite are in good agreement with previous measurements for other garnets and are considerably lower than thermal diffusivities of wadsleyite and ringwoodite, which are the main components of the mantle transition zone. We discuss the implications of the low thermal conductivity of subducted oceanic crust in the transition zone for the triggering of deep seismicity.

Translated title of the contribution	Thermal diffusivity of MORB-composition rocks to 15 GPa: implications for triggering of deep seismicity
Original language	English
Pages (from-to)	406-414
Number of pages	9
Journal	High Pressure Research
Volume	30
Issue number	3
Early online date	8 Sept 2010
DOIs	https://doi.org/10.1080/08957959.2010.516827
Publication status	Published - 2010

Bibliographical note

Date of Acceptance: 17/08/2010

Research Groups and Themes

PetrologyGroup
PetrologyLabs

Keywords

thermal diffusion
MORB
majorite
deep earthquakes
high pressure

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10.1080/08957959.2010.516827

Dobson et al HPR 2010 GREEN
This is an Accepted Manuscript of an article published by Taylor & Francis in High Pressure Research on 08/09/2010, available online: http://wwww.tandfonline.com/doi/ref/10.1080/08957959.2010.516827.
Accepted author manuscript, 728 KB

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@article{106bd1baa9f942dbbcb29e5daa1f4b85,

title = "Thermal diffusivity of MORB-composition rocks to 15 GPa: implications for triggering of deep seismicity",

abstract = "We have measured the thermal diffusivity of eclogite and majorite with a model MORB composition at pressures of 3 and 15 GPa, respectively. Both phase assemblages show inverse dependences of their thermal diffusivities on temperature: D eclogite=9(10)×10−10+7(1)×10−4/T(K) m 2/s and D majorite=6.2(5)×10−7+3.0(5)×10−4/T(K) m 2/s. The values for majorite are in good agreement with previous measurements for other garnets and are considerably lower than thermal diffusivities of wadsleyite and ringwoodite, which are the main components of the mantle transition zone. We discuss the implications of the low thermal conductivity of subducted oceanic crust in the transition zone for the triggering of deep seismicity.",

keywords = "thermal diffusion, MORB, majorite, deep earthquakes, high pressure",

author = "Dobson, {David P} and Hunt, {Simon A} and Richard McCormack and Lord, {Oliver T} and {Donald J.}, Weidner and Li Li and Walker, {Andrew M}",

note = "Date of Acceptance: 17/08/2010",

year = "2010",

doi = "10.1080/08957959.2010.516827",

language = "English",

volume = "30",

pages = "406--414",

journal = "High Pressure Research",

issn = "0895-7959",

publisher = "Taylor & Francis Group",

number = "3",

}

TY - JOUR

T1 - Thermal diffusivity of MORB-composition rocks to 15 GPa

T2 - implications for triggering of deep seismicity

AU - Dobson, David P

AU - Hunt, Simon A

AU - McCormack, Richard

AU - Lord, Oliver T

AU - Donald J., Weidner

AU - Li, Li

AU - Walker, Andrew M

N1 - Date of Acceptance: 17/08/2010

PY - 2010

Y1 - 2010

N2 - We have measured the thermal diffusivity of eclogite and majorite with a model MORB composition at pressures of 3 and 15 GPa, respectively. Both phase assemblages show inverse dependences of their thermal diffusivities on temperature: D eclogite=9(10)×10−10+7(1)×10−4/T(K) m 2/s and D majorite=6.2(5)×10−7+3.0(5)×10−4/T(K) m 2/s. The values for majorite are in good agreement with previous measurements for other garnets and are considerably lower than thermal diffusivities of wadsleyite and ringwoodite, which are the main components of the mantle transition zone. We discuss the implications of the low thermal conductivity of subducted oceanic crust in the transition zone for the triggering of deep seismicity.

AB - We have measured the thermal diffusivity of eclogite and majorite with a model MORB composition at pressures of 3 and 15 GPa, respectively. Both phase assemblages show inverse dependences of their thermal diffusivities on temperature: D eclogite=9(10)×10−10+7(1)×10−4/T(K) m 2/s and D majorite=6.2(5)×10−7+3.0(5)×10−4/T(K) m 2/s. The values for majorite are in good agreement with previous measurements for other garnets and are considerably lower than thermal diffusivities of wadsleyite and ringwoodite, which are the main components of the mantle transition zone. We discuss the implications of the low thermal conductivity of subducted oceanic crust in the transition zone for the triggering of deep seismicity.

KW - thermal diffusion

KW - MORB

KW - majorite

KW - deep earthquakes

KW - high pressure

U2 - 10.1080/08957959.2010.516827

DO - 10.1080/08957959.2010.516827

M3 - Article (Academic Journal)

SN - 0895-7959

VL - 30

SP - 406

EP - 414

JO - High Pressure Research

JF - High Pressure Research

IS - 3

ER -

Thermal diffusivity of MORB-composition rocks to 15 GPa: implications for triggering of deep seismicity

Abstract

Bibliographical note

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Keywords

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