Fluid flow and mass flux determinations at vent sites on the Cascadia margin accretionary prism

Journal Article · Sun Jun 10 04:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JB095iB06p08891· OSTI ID:5009586

Carson, B; Strasser, J C ^[1]; Suess, E ^[2]

---

1. Lehigh Univ., Bethlehem, PA (United States)
2. Oregon State Univ., Corvallis (United States)

Fluid venting from the toe of the accretionary prism off Oregon was measured in situ during a series of dives with DSRV Alvin in 1987 and 1988. A benthic chamber was place over active vent sites to sequentially collect samples of venting fluids and to make direct measurements of discharge rates. Calibrated flow meter measurements and flow rates determined from dissolved methane transfer indicate that discharge from two vent sites, Alvin 1428 and Alvin 1900, ranges roughly between 100 and 500 l/m{sup 2}d with the most reliable estimates falling in the range of 125-150 l/m{sup 2}d. These rates imply subsurface advective flow on the order of 100 m/yr. Comparison of observed discharge rates with rates calculated for steady state expulsion supported by accretion-related compaction indicates that the observed flow is greater than predicted flow by several orders of magnitude. The disparity dictates that fluids are not derived locally, but are transported laterally within the prism, or that flow is not steady state and that individual vents are short-lived features in the ongoing accretion process.

• OSTI ID: 5009586
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:B6; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ALKANES
AQUATIC ORGANISMS
BENTHOS
DEVELOPED COUNTRIES
FEDERAL REGION X
FLOW RATE
FLOWMETERS
FLUID FLOW
FLUIDS
GEOLOGIC STRUCTURES
GROUND WATER
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROLOGY
INTERSTITIAL WATER
MASS TRANSFER
MEASURING INSTRUMENTS
METERS
METHANE
NORTH AMERICA
OREGON
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
RESERVOIR FLUIDS
SUBDUCTION ZONES
USA
VENTS
WATER