Submitted by Anonymous on Sun, 04/27/2008 - 08:55
Forums
Bering Sea Benthic Studies

ms. davenport,

i was wondering how long does it usually take to get a core sample from the multicorer, and if it is easy to operate?

Trevor W. at Hartford High

Mon, 04/28/2008 - 08:43

Emily S. Davenport

Hi Trevor!
Well, samples from the multicorer vary, depending on how deep the water is. In a shallow station, say 70-140 meters (200-400 feet deep) it takes about 20-30 minutes round trip for the multicorer to go down and back. We get up to 8 samples from it at once, and we send the multicorer down 2 times (sometimes more if we don't get many good samples). Deeper stations require more time, because you have to let the multicorer go down slowly so you don't damage it. Our deep water stations (3000 meters, 9000+ feet) take 3 1/2 hours for 1 drop of the multicore!!! That's a long time!! The multicore is pretty easy to operate, we just hook it up to the A-frame on the back of the boat, and there is someone in the control room on board the ship that lowers it over the side, with direction from some of the Coast Guard marine science technicians on board. Paul, our coring technician, makes sure that they lower the multicorer at the correct speed and that it gets placed on the bottom as nicely as possible, to keep from damaging it. He also records the depth and time it reached the bottom and our location (latitude and longitude).
Once we get a sample from the multicorer, it takes up to 4 hours to process those samples- dividing them up for the different types of analyses. Overall, it takes about 24 hours to deploy the multicorer and process all the samples- which is why we don't core every day!! Phew, we'd be exhausted!!
Thanks for your question!