Open AccessHeat flow bounds over the C ascadia margin derived from bottom simulating reflectors and implications for thermal models of subduction
Author(s) -
Phrampus Benjamin J.,
Harris Robert N.,
Tréhu Anne M.
Publication year - 2017
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1002/2017gc007077
Subject(s) - geology , subduction , thermal , geophysics , petrology , basement , hydrothermal circulation , flow (mathematics) , sediment , margin (machine learning) , seismology , mechanics , geomorphology , tectonics , meteorology , physics , civil engineering , machine learning , computer science , engineering
Understanding the thermal structure of the Cascadia subduction zone is important for understanding megathrust earthquake processes and seismogenic potential. Currently our understanding of the thermal structure of Cascadia is limited by a lack of high spatial resolution heat flow data and by poor understanding of thermal processes such as hydrothermal fluid circulation in the subducting basement, sediment thickening and dewatering, and frictional heat generation on the plate boundary. Here, using a data set of publically available seismic lines combined with new interpretations of bottom simulating reflector (BSR) distributions, we derive heat flow estimates across the Cascadia margin. Thermal models that account for hydrothermal circulation predict BSR‐derived heat flow bounds better than purely conductive models, but still over‐predict surface heat flows. We show that when the thermal effects of in‐situ sedimentation and of sediment thickening and dewatering due to accretion are included, models with hydrothermal circulation become consistent with our BSR‐derived heat flow bounds.