The Nicoya convergent margin; a region of exceptionally low heat flow

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doi: 10.1029/96GL00733
Author(s): Langseth, Marcus G.; Silver, Eli A.
Author Affiliation(s): Primary:
Lamont-Doherty Earth Observatory, Palisades, NY, United States
Other:
University of California at Santa Cruz, United States
Volume Title: Fluid flow in the Costa Rica accretionary prism
Volume Author(s): Silver, Eli A., prefacer
Source: Fluid flow in the Costa Rica accretionary prism, prefaced by Eli A. Silver. Geophysical Research Letters, 23(8), p.891-894. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0094-8276 CODEN: GPRLAJ
Note: In English. 12 refs.Special section; illus., incl. sect., 2 tables, geol. sketch maps
Summary: Over 100 measurements of seafloor heat flow reveal that the accretionary complex adjacent to the Nicoya Peninsula is characterized by remarkably low heat flow; values over the accretionary prism average 28 mW/m2, and values in the trench and the ocean crust seaward of the trench average 14 mW/m2. We attribute the low heat flow to effective hydrothermal cooling of the upper crust on the subducting plate and suggest that extensional faults created by flexure of the lithosphere enhance hydrothermal circulation. Thermal models show that subduction of low temperature crust combined with significant frictional heating at the decollement can explain the low and uniform heat flow. Disparity between heat flow values observed on the lower trench slope with model results suggests upward advection of heat by porewater flux through broadly distributed conduits. Copyright 1996 by the American Geophysical Union.
Year of Publication: 1996
Research Program: ODP Ocean Drilling Program
Key Words: 18 Geophysics, Solid-Earth; Accretionary wedges; Alvin; Central America; Costa Rica; Costa Rica accretionary wedge; Crust; East Pacific; Fluid pressure; Heat flow; Hydrothermal conditions; Hydrothermal vents; Leg 112; Middle America Trench; Movement; Nicoya Peninsula; North Pacific; Northeast Pacific; Ocean Drilling Program; Oceanic crust; Pacific Ocean; Plate convergence; Plate tectonics; Pore water; Subduction; Submersibles
Coordinates: N093000 N095500 W0860000 W0861500
Record ID: 1997020569
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.