Here is the Deployment Summary Table
This is the preliminary report with some plots and data files appended at the end.
STRATAFORM
VIMS
PRELIMINARY DATA REPORT
November 1996 - January 1997
D. A. Hepworth, C. T. Friedrichs and L. D. Wright
School of Marine Science
Virginia Institute of Marine Science
The College of William and Mary
Gloucester Point ,Virginia 23062.
1. Introduction
During the period November 1996 - January 1997 five VIMS scientists and technicians participated in STRATAFORM. The objective was to deploy and recover two instrumented tripods, one at the G-30 site and one at the G-60 site. The participants in the VIMS field component were: Franklin Farmer, Robert Gammisch, Daniel Hepworth, Todd Nelson, and Wayne Reisner.
2 Tripod Deployments
The tripod deployed were to obtain estimates of time-varying bed stress over contrasting bottom types at two sites and to evaluate sediment resuspension in response to those stresses. Secondarily, the instruments were intended to add data on waves and mean currents for use by all STRATAFORM investigators.
Instrumentation
The two tripods deployed by VIMS were similar in configuration and rigged primarily to collect benthic boundary layer profiles of velocity and suspended sediment concentration as well as to provide general information on waves and mean currents. The five main instruments on each tripod were designated as the 635, 626, OBS, ADV, and an upward looking water column velocity profiler. The G-30 tripod carried a 635 with a single electro-magnetic Marsh-McBirney velocity sensor and a Paroscientific pressure gage located at elevations of 134 and 244 cm above the bed respectfully. The 626 collected velocity profiles using four Marsh-McBirney sensors at 12, 42, 73, and 103 cm and pressure at 249 cm above the bed. The OBS used five Downing infrared optical backscatter sensors for suspended sediments profile determination at 12, 30, 48, 63, and 73 cm above the bed. At G-60, the 635 velocity sensor was at 134 cm and the pressure gage at 205 cm above the bed. The 626 velocity sensors were at 12, 43, and 72 cm (only three senors) and pressure at 251 cm and OBS sensors at 13, 32, 42, 63, and 73 cm above the bed. All of these instruments were programmed to record data every 4 hours and collect 2048 samples at 1 second intervals (approx. 34 minutes of data). The ADV on the G-30 pod measured three-component velocity (xyz) at a point 24 cm above the bed. The ADV on the G-60 pod sampled the velocity at 21 cm above the bed. These instruments were programmed to record data every 4 hours and collect 3500 samples at 0.2 second intervals (approx. 12 minutes of data). A Sontek Acoustic Doppler Profiler was mounted on the G-30 pod about 2.5 meters above the bed. It was programmed to make water column profiles every 8 minutes with 0.5 meter resolution. A RDI Acoustic Doppler Current Profiler mounted on the G-60 pod at 2.6 meters above the bed was programmed to collect profiles every 30 minutes with 0.5 meter resolution. Profiles started at about 6 meters above the bed.
Ship's Log
The VIMS tripod was assembled and ready for deployment on November 20, 1996. On November 21, 1996 the F/V Warrior II arrived at Fields Landing (Eureka, CA) to load both of the VIMS pods and one United States Geological Survey (USGS) pod. A problem with the USGS pod precluded any deployments that day, but the next day all three pods were deployed. The G-30 pod was deployed at 40 41.42' N, 124 21.25 W and at a depth of approx. 31 meters and the G-60 pod at 40 43.36' N, 124 25.09 W at a depth of about 64 meters.
On January 27, 1997 the Warrior II recovered the G-60 pod, however the G-30 pod was not recovered (and has not been recovered as of August 1997).
Data Return and Preliminary Processing
From the G-60 pod we retrieved more than 2 months (at 6 bursts a day) of pressure, velocity, and suspended sediment data. The upward
looking acoustic water column profiler logged 3170 water column velocity profiles. The ADV
did not collect any data.
Here is the Deployment Summary Table
Burst-Mean Summary Plots
635 - Velocity and Depth
626 - Velocity Profile and Pressure
OBS - Sediment and Temperature
What Burst Data Looks Like (at 20:00 GMT 7 Dec 1996)
635
626
OBS
ADCP Data (Whole Deployment Low Pass Filtered)
Water Column Current Magnitudes
Current Headings
Burst-Mean Summary Files
Burst Data Files
Request for burst data should be emailed to: hepworth@vims.edu
with cc to: wright@vims.edu
(There is approx. 100 megabytes of processed data alone!)