Pacific Coastal and Marine Science Center
Monterey Bay Studies
1995 Current and Sediment Study in Monterey Canyon
Moorings were deployed for a year in Monterey Canyon across
Each mooring had current meters, transmissometers, and sediment traps.
The largest currents in the canyon were tides, which mainly flowed up and down the canyon. The largest current speeds were near the bed, and tides in the narrow portion of the canyon were four times larger than in wider sections.
An unusual 3-day oscillation was observed in the canyon for the entire deployment period. The oscillation had large spatial scales because it was seen simultaneously at all sites along the canyon axis, spanning a horizontal distance of 75 km and a vertical distance of 2000 m. We are currently investigating the cause of the oscillation.
A sediment trap was deployed 80 m above the bed in the narrow axis, large amounts of particles and other material settled into the trap: 22-60 grams per square meter per day. The trap overflowed after 3 months.
Subsequently, a very large turbidity event occurred that lasted more than a week. In 4 hours, the water column went from clear to very cloudy, the pressure changed, and the water became slightly warmer and fresher. We think this material either slumped off the canyon walls or came down the canyon as a turbidity current.
A few definitions:
Participating scientists and agencies:
The study was jointly funded by the U.S. Geological Survey and Office of Naval Research.