Heat-flow determination in three DSDP boreholes near the Japan trench

Journal Article · Sat Oct 10 04:00:00 EDT 1981 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB086iB10p09411· OSTI ID:5543181

Burch, T K; Langseth, M G

The first deep borehole determinations of temperature gradients and heat flow of the landward wall of the Japan Trench and forearc were made on IPOD DSDP leg 57. These heat flow values are based on temperature logs corrected to equilibrium, using a detailed model of the drilling disturbance. Heat flow values on a deeply submerged terrace, landward of the trench slope break are 28 and 32 mW m/sup -2/. A measurement in the midslope terrace basin on the landward wall of the trench yielded a value of 22 mW m/sup -2/. The results are in good agreement with earlier seafloor measurements and indicate that most of the forearc area is characterized by heat flow about one half of that over oceanic lithosphere seaward of the trench. Our observations indicate only a small increase of heat flow from the trench to the volcanic arc, in agreement with thermal models, which suggests that the subduction of the relatively cold oceanic plate continues to dominate the temperature structure for distances of up to 250 km landward of the trench. The temperature profile in the borehole on the midslope terrace indicates possible vertical flow of pore waters. Hundreds of conductivity determinations were made using a new technique.

• Research Organization: Lamont-Doherty Geological Observatory, Palisades, New York 10964
• OSTI ID: 5543181
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 86:B10; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
BOREHOLES
CAVITIES
EARTH CRUST
HEAT FLUX
OCEANIC CRUST
PACIFIC OCEAN
PHYSICAL PROPERTIES
PLATE TECTONICS
SEA BED
SEA-FLOOR SPREADING
SEAS
SURFACE WATERS
TECTONICS
TEMPERATURE GRADIENTS
TEMPERATURE MEASUREMENT
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES