The thermal environment of Cascadia Basin
Article first published online: 10 JUL 2012
©2012. American Geophysical Union. All Rights Reserved.
Geochemistry, Geophysics, Geosystems
Volume 13, Issue 7, July 2012
How to Cite
2012), The thermal environment of Cascadia Basin, Geochem. Geophys. Geosyst., 13, Q07003, doi:10.1029/2011GC003922., , and (
- Issue published online: 10 JUL 2012
- Article first published online: 10 JUL 2012
- Manuscript Accepted: 5 JUN 2012
- Manuscript Revised: 25 MAY 2012
- Manuscript Received: 17 OCT 2011
- National Science Foundation. Grant Numbers: Grants OCE-0452565, OCE-1037870
- Washington Sea Grant. Grant Number: R/NP-6
- heat flow;
 Located adjacent to the NE Pacific convergent boundary, Cascadia Basin has a global impact well beyond its small geographic size. Composed of young oceanic crust formed at the Juan de Fuca Ridge, igneous rocks underlying the basin are partially insulated from cooling of their initial heat of formation by a thick layer of pelagic and turbidite sediments derived from the adjacent North American margin. The igneous seafloor is eventually consumed at the Cascadia subduction zone, where interactions between the approaching oceanic crust and the North American continental margin are partially controlled by the thermal environment. Within Cascadia Basin, basement topographic relief varies dramatically, and sediments have a wide range of thickness and physical properties. This variation produces regional differences in heat flow and basement temperatures for seafloor even of similar age. Previous studies proposed a north-south thermal gradient within Cascadia Basin, with high geothermal flux and crustal temperatures measured in the heavily sedimented northern portion near Vancouver Island and lower than average heat flux and basement temperatures predicted for the central and southern portions of the basin. If confirmed, this prediction has implications for processes associated with the Cascadia subduction zone, including the location of the “locked zone” of the megathrust fault. Although existing archival geophysical data in the central and southern basin are sparse, nonuniformly distributed, and derived from a wide range of historical sources, a substantial N-S geothermal gradient appears to be confirmed by our present compilation of combined water column and heat flow measurements.