Monterey Bay Aquarium Research Institute
2004 projects
Benthic Processes

Canyon Dynamics

Project Manager: Bill Ussler
Lead Scientist: Charlie Paull

The main focus of the Canyon Dynamics project—initiated in 2001—is to obtain a better understanding of the sediment transport processes that occur within Monterey Canyon. A number of activities are planned for 2004:(1) Work with the MOOS project on the deployment of one remote instrument node, a sediment trap, and a benthic vertical profiler in the axis of Monterey Canyon channel at Shepard Meander (at ~3,600 meters depth). The scientific goal is to understand the passage of material through the lower canyon.

(2) Conduct repeat mapping surveys of a section of the upper Monterey Canyon floor, using the new Reson multibeam sonar system. Repetitive mapping across the canyon axis will reveal how the channel depth changes with time. This will allow us to begin to estimate the volumes of material that are moving in sediment transport events.

3) Analyze the conductivity, temperature, depth, oxygen, and transmissivity (CTDOT) data within the MBARI archives, using the Shore Side Data System (SSDS). The objectives are to address an open science question related to Canyon Dynamics and to test SSDS for observatory-based science with a real application. Transmissometer data collected during ROV dives over the past 10 years in the axis of Monterey Canyon reveal that a persistent tongue of very turbid water commonly occurs which is confined to the axial channel of the canyon. These turbidity plumes have previously escaped detection probably because surface vessels are reluctant to run standard CTD hydrocasts to the bottom, especially in areas of complicated topography. We now suspect that these slugs of extremely turbid waters are part of a previously undocumented, but potentially important material transport pathway. 

(4) Conduct event response cruises to measure the physical conditions and to capture the suspended materials associated with major sediment transport events in Monterey Canyon while they are still happening, or shortly afterwards. Sediment transport events are most like to occur when the Salinas River floods, following moderate earthquakes or during exceptionally heavy sea conditions. Because the timing of such events is unpredictable, we cannot schedule these sampling activities in advance but are prepared respond rapidly when an event occurs.

(5) Use Tiburon's vibracoring system to collect transects of cores across the axial channel that passes through the lower canyon and across Monterey Fan. The objective will be to establish the stratigraphy of the axial channel floor at the downstream end of Monterey Canyon. While studies in the upper canyon have provided critical information on the nature of these events, we now plan to compliment these observations by sampling the deposits that these events produce.

Last updated: Feb. 05, 2009