Long-distance fluid and heat transport in the oceanic crust entering the Nankai subduction zone, NanTroSEIZE transect

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doi: 10.1016/j.epsl.2013.12.013
Author(s): Spinelli, Glenn A.
Author Affiliation(s): Primary:
New Mexico Institute of Mining and Technology, Earth and Environmental Science Department, Socorro, NM, United States
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, Vol.389, p.86-94. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. Includes appendices. 63 refs.; illus., incl. 3 tables, sketch map
Summary: I examine the potential causes of anomalous seafloor heat flux on the oceanic plate in the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) transect offshore southern Japan. The most prominent anomaly is a ∼50 mWm-2 change in heat flux between Integrated Ocean Drilling Program Sites C0011 and C0012 over a distance of <10 km. I develop thermal models to investigate the effects of hydrothermal circulation in the basaltic basement of the oceanic crust and variations in heat input from the mantle. The <10 km wide transition in surface heat flux reflects a process in the shallow subsurface; variations in heat input from ≥5 km depth would generate a >30 km wide transition at the seafloor. The observed surface heat flux pattern is indicative of hydrothermal circulation in the basement aquifer and advection of heat from the subducted crust into the aquifer on the incoming plate. For a 600 m thick aquifer, the permeability is likely ≥7×10-11 m2, and hydrothermal circulation transports at least 300 times more heat than conduction alone. The heat flux from the subduction zone seaward to the incoming plate is consistent with hydrothermal circulation in the subducting crust persisting to -100 km landward of the deformation front. Vigorous fluid circulation in the basaltic basement is consistent with both the seafloor thermal anomalies and geochemical anomalies near the sediment-basement interface. Abstract Copyright (2014) Elsevier, B.V.
Year of Publication: 2014
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 18 Geophysics, Solid-Earth; Advection; Aquifers; Crust; Finite element analysis; Fluid phase; Geothermal systems; Heat flux; Heat transfer; Heating; Hydrothermal conditions; IODP Site C0011; IODP Site C0012; Integrated Ocean Drilling Program; NanTroSEIZE; Nankai Trough; North Pacific; Northwest Pacific; Oceanic crust; Pacific Ocean; Permeability; Plate tectonics; Shikoku Basin; Subduction; Subduction zones; Thermal anomalies; West Pacific
Coordinates: N324944 N324945 E1365256 E1365254
N324453 N324453 E1365501 E1365501
Record ID: 2014025782
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands