Ship: R/V WECOMA
Depart Kodiak, Alaska 5/10/99
NOAA, Pacific Marine Environmental Laboratory (PMEL)
Cruise Description and Objectives:
The objectives for this cruise are:
1.1 Chief Scientist: Keith Roberts PMEL
1.2 Participating Scientist:
Name, Sex, Nationality, Affiliation
The following Mooring items will be loaded on WECOMA prior to departure from Newport, OR
Item, Item Weight, Number, Total
Total = 3,270 lbs.2.2 Underway Operations
Operations will consist of mooring
recoveries and deployments and ADCP transects (time permitting). (See attachments
1 & 2)
BPR, Station Latitude (N), Longitude
(W), Depth [m]
Coordinates for the Pavlof bay mooring:
Station Latitude (N), Longitude
(W), Depth [m]
Coordinates and speed for the ADCP transect lines:
ADCP Line, Latitude, Longitude,
2.3 Equipment Loading/ Off-loading
All mooring equipment and instrumentation will be loaded on the ship prior to the ship’s departure from Newport, OR. All equipment and instrumentation will be off-loaded in Seattle, WA when the ship returns, on or about 15 June 1999.
2.4 BPR Mooring Descriptions
The Tsunami Bottom Pressure Recorder (BPR) mooring configuration (Attachment 3) consists of an expendable steel plate anchor attached to a combination aluminum tripod and platform. Mounted on the platform are an acoustic release, the BPR pressure case, a Paroscientific pressure sensor, and a Miniature Temperature Recorder (MTR). Flotation is provided by seven Benthos glass spheres with yellow propylene hardhats fastened to a seven-pack holder. An orange signal flag, transmitter, and strobe light are attached, to aid in locating and recovering the moorings when they are at the surface.
2.5 BPR Recovery/Deployment Procedures
The EG&G Ocean Products Model 8011 deck unit will be used for both the recovery and deployment operations. During recovery operations the ship will heave to and attempt recovery using a transducer lowered over the side. The ship should remain DIW with the screws secured (to prevent noise interference) for this operation. The acoustic release will then be interrogated and the anchor released, allowing the BPR to float to the surface (which takes approximately one hour). Once the unit is on the surface it can be recovered using a grappling hook or a small boat, if weather permits. The float-ring is equipped with a strobe and a transmitter (which broadcasts on Ch. 70, or 156.525 MHz) to assist in locating the mooring when on the surface.
During deployment, the acoustic release’s transducer is used to provide ranging information and track the mooring’s descent. The ship should remain DIW with the screws secured until the unit's position on the bottom is verified. When the instrument is determined to be on the bottom, a code is sent to disable the release.
2.6 PROCEDURES FOR ADCP OPERATIONS:
The following FOCI operations are to be conducted on this cruise on a not-to-interfere basis.
Vessel-mounted acoustic Doppler current profiler (VM-ADCP) observations will be collected with the 150 kHz RDI ADCP on NOAA/PMEL cruises using Version 2.48 of RDI’s DAS software running with user exit UE4.EXE on the dedicated DOS computer. Data are usually logged on 3.5-inch floppy diskettes that are brought back for processing. One or more DAS configuration files specifying the system settings will usually be provided. One configuration file may be used in deep water (> 500 m, but dependent upon weather conditions) where bottom tracking is not possible, and another with bottom tracking enabled may be used in shallow water. When operating plans call for the ship repeatedly to cross this depth horizon or for operations to be only incidentally in shallow water, the no-bottom-tracking configuration is usually used.
The ADCP system should be configured to use the ship’s gyrocompass for heading, a P-code encrypted GPS receiver for positioning and the Ashtech 3DF attitude determination unit to provide supplementary heading information to DAS via user exit 4. If the P-code GPS fails, a differential GPS receiver should be substituted. Normally the ADCP is set up with an 8 m transmit pulse and bin size, a 4 m blank after transmit, 1 s pulse cycle time, and a 5 minute sampling interval.
2.6.1 Station Information:
It is requested that the position of each operation and station be maintained in a log with GMT date & time, position and depth. At a minimum, the following items should be logged:
3.1 Equipment and Supplies provided by the Ship
The following systems and their support services are essential to the project. Sufficient consumables, back-up units, and on-site spares and technical support must be in place to assure efficient operations. All instruments used for scientific measurements are expected to have current calibrations, and all pertinent calibration information shall be included in the data package.
4.1 Data Requirements
The following data products should be included in the cruise data package at the end of the cruise:
Station log sheets
4.2 Station Log:
The bridge watch during the cruise will maintain a station log. The critical information to record at each station is:
GMT date, GMT time, Position, Station #, Bottom depth.
5.0 ADDITIONAL INVESTIGATIONS AND PROJECTS
Any additional work will be subordinate to the main project and will be accomplished with concurrence of the Chief Scientist and on a not-to-interfere basis.
5.1 ADCP Piggyback Project
The Fisheries-Oceanography Coordinated Investigation (FOCI) will conduct four Acoustic Doppler Current Profiler transects as outlined in Sections 2.2 and 2.6. The FOCI operation's work will require the ship to maintain a speed of 10 knots (12 knots may be achieved, weather permitting) during each transect. The ship is to maintain course; however, adjustments for set and drift may be necessary. The bottom track mode must be secured.
INMARSAT should be made available to the Chief Scientist for communication with the laboratory.
Attachment 1 BPR sites
Attachment 2 Operations Spread Sheet
Attachment 3 BPR Configuration