Thermal studies at the Middle America Trench offshore Costa Rica and Nankai Trough, Japan

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http://abstractsearch.agu.org/meetings/2011/FM/T12A-01.html
Author(s): Harris, R. N.; Solomon, E. A.; Spinelli, G. A.
Integrated Ocean Drilling Program, Expedition 334 Scientific Team
Author Affiliation(s): Primary:
Oregon State University, COAS, Corvallis, OR, United States
Other:
University of Washington, School of Oceanography, United States
New Mexico Institute of Mining and Technology, Department of Earth & Environmental Science, United States
Volume Title: AGU 2011 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2011; American Geophysical Union 2011 fall meeting, San Francisco, CA, Dec. 5-9, 2011. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: Knowledge of the temperature distribution at convergent margins is important to understanding physical and chemical processes such as fluid flow, diagenesis, and faulting mechanics in the forearc region. Seafloor probe measurements offer an economical method for obtaining transects of heat flow across the forearc and along strike. Because these measurements only prick the seafloor they are sensitive to near seafloor processes such as bottom water temperature variations, deformation, and shallow fluid circulation and, although important in their own right, can obfuscate thermal inferences at depth. Ocean drilling provides access to deeper environments where downhole tools, acoustic measurements, and logging technologies can provide important scientific insight. We review recent heat flow results from the Costa Rica and Nankai convergent margins emphasizing ocean drilling transects where measurements of heat flow are available from seafloor probe and ocean drilling. Heat flow measurements offshore the erosive Costa Rican margin show strong along strike variations that reflect different styles of fluid flow and have important impacts on forearc processes. Along both the Nicoya and CRISP drilling transects, heat flow from seafloor probes and ocean drilling are consistent and indicate hydrothermal circulation prior to and after subduction. Fluid flow advects heat from deeper along the subduction thrust and deposits it near the seafloor cooling and warming these regions, respectively. The accretionary Nankai Trough also shows important along strike changes in heat flow related to the age of oceanic crust at the trench. Heat flow and geochemical results are consistent with basement fluid flow at the Muroto transect but are more ambiguous at the NanTroSEIZE transect.
Year of Publication: 2011
Research Program: IODP Integrated Ocean Drilling Program
IODP2 International Ocean Discovery Program
Key Words: 16 Structural Geology; Accretionary wedges; Asia; Central America; Costa Rica; East Pacific; Far East; Faults; Geotraverses; Heat flow; Hydrothermal conditions; Integrated Ocean Drilling Program; International Ocean Discovery Program; Japan; Middle America Trench; Muroto Transect; NanTroSEIZE; Nankai Trough; North Pacific; Northeast Pacific; Northwest Pacific; Ocean floors; Offshore; Pacific Ocean; Tectonophysics; Thermal anomalies; West Pacific
Record ID: 2015100782
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by, and/or abstract, Copyright, American Geophysical Union, Washington, DC, United States

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