NOAA Teacher at Sea
Onboard U.S. Coast Guard Vessel Healy
July 1 – 30, 2008
Mission: Bering Sea Ecosystem Survey
Geographic Region: Bering Sea, Alaska
Date: July 11, 2008
They are the men of the back deck, working diligently to prepare and then release their moorings in depth determined locations, where they will settle (literally) for a year. These unsung heroes are the mooring men!
For the past week I have been observing a lot of scientific research and much has been based on living critters, but there is so much more occurring on the HEALY this summer. Under the guidance of Tom Weingartner, the mooring men have been working diligently to not only construct, but then release their moorings which will stay here in the Bering, collect data and then be retrieved, next year!
So what then is a mooring, well this specific example is a bottom mounted instrument, or “Spider C40.” You will notice that the “Spider” is chock full of sampling equipment, there is an: acoustic Doppler current profiler, flurometer, Sea Cat, and transmissometer. Each one of these instruments is designed to collect specific data, which will be saved then interpreted next year.
The “spider” commonly referred to as Helen, is the second of three instruments being placed on what is known as the central ray to the south of Nunivak Island. There are three ” mooring rays,” central, southern and northern, and placed on each will be a series of three mooring. At this time Tom is working on a three year NSF grant. What exactly is Tom learning from this data, well check in tomorrow for a more in-depth look at what scientists learn from moorings? I would though like to go into a bit of detail on the deployment of a “spider” to the bottom of the Bering.
This Spider was deployed in 25 meters of water. Its objective to sit firmly on the bottom.
Not only is this mooring going to the bottom, but it has two acoustic release mechanisms, one to be used in a year to bring the entire mooring back to the surface, and the other to be used, right now. For a controlled fall, the spider is securely placed on the sea floor by the MST team using a 3/8inch winch wire. Kevin will then send a 12 kilohertz signal telling the second release mechanism to let go.
Once the signal is sent to the acoustic release, the line to the ship is let loose, and then a GPS bearing taken so that in a year the scientists will be able to retrieve the mooring and all the wonderful data it has collected.
Check in tomorrow for a continuation with the mooring men and the science behind why they are setting these moorings, and what they will do with the data. We will also look at the actual construction of a mooring onboard.
Quote of the Day: What is life? It is the flash of a firefly in the night. It is the breath of a buffalo in the wintertime. It is the little shadow which runs across the grass and looses itself in the sunset. -Crowfoot
FOR MY STUDENTS: Do you think we could construct a simple mooring to record data from the pond?