| Title | Effects of fluid circulation in subducting crust on Nankai margin seismogenic zone temperatures |
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| Author | Spinelli, G A; Wang, K |
| Source | Geology vol. 36, no. 11, 2008 p. 887-890, https://doi.org/10.1130/G25145A.1 |
| Image |  |
| Year | 2008 |
| Alt Series | Earth Sciences Sector, Contribution Series 20080351 |
| Publisher | Geological Society of America |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Area | Nankai Margin; Nankai Trough; Japan |
| Lat/Long WENS | 132.0000 137.0000 34.5000 31.0000 |
| Subjects | tectonics; structural geology; subduction zones; subduction; temperature; geothermal temperatures; anomalies; oceanic crust; permeability; hydrothermal systems; seismicity; structural features; faults;
fault zones; modelling; models |
| Illustrations | location maps; graphs; plots; cross-sections |
| Program | Reducing Risk from Natural Hazards |
| Released | 2008 01 01 |
| Abstract | Vigorous fluid circulation maintained in newly subducted ocean crust significantly affects subduction zone temperatures on the Nankai margin, Japan. The shallow part of the igneous ocean crust is
pervasively fractured and thus highly permeable, allowing vigorous hydrothermal circulation. This circulation has been recognized as an important control on the thermal budget and evolution of ocean crust worldwide. However, existing subduction zone
thermal models either do not include hydrothermal circulation in ocean crust or assume that it abruptly stops upon subduction. Here, we use a conductive proxy to incorporate the thermal effects of high Nusselt number fluid circulation in subducting
crust into a subduction zone thermal model. Hydrothermal circulation reduces temperatures in the seismogenic zone of the Nankai margin plate boundary fault by ~20 °C at the updip limit of seismicity and ~100 °C at the downdip limit. With improved
thermal models for subduction zones that include the effects of hydrothermal circulation in subducting crust, estimates of metamorphic reaction progress and interpretations of fault zone processes on various margins may need to be revisited.
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| GEOSCAN ID | 225735 |
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