Jillian Worssam, July 11, 2008

NOAA Teacher at Sea
Jillian Worssam
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

Meet Kevin, Jimmy, John and Dave, all ready for mooring action on the Bering Sea!
Meet Kevin, Jimmy, John and Dave, all ready for mooring action on the Bering Sea!

Science Log

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!

With various forms of sampling equipment the Spider C40
With various forms of sampling equipment the Spider C40

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.

AS the winch raises the instrument array, the scientists and MST team work in tandem to make sure everyone is safe and the deployment successful.
AS the winch raises the instrument array, the scientists and MST team work in tandem to make sure everyone is safe and the deployment successful.

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.

Kevin is setting up the electronics equipment necessary to release the mooring after placement on the sea floor.
Kevin is setting up the electronics equipment necessary to release the mooring after placement on the sea floor.

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.

Using the GPS to get an accurate location so that the team can come back for a pinpoint retrieval.
Using the GPS to get an accurate location so that the team can come back for a pinpoint retrieval.

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?

Those mooring men are working him to exhaustion! Thank goodness for the excellent food on board!
Those mooring men are working him to exhaustion! Thank goodness for the excellent food on board!

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