It’s been a long time since I last posted. We are now 20 days in and also twenty days away till we return to Narragansett. Things are settling down a bit and we are finally getting into a rhythm. The routine is usual now, in that there are few surprises. The unfamiliar person may be confused when I say surprise, but on this trip, the last thing we want is a surprise. As far as everybody is concerned, no one wants surprises.
This morning, I un-officially became an expert at reading the echo sounder display for pinger traces. When we send our sampler below, we attach a pinger (beacon) device along for the ride. This is done to monitor our progress towards the Sea floor. The pinger behaves like a strobe in that it transmits a pulse. The pulse is a pressure wave (sound) that we measure to calculate the distance which the package has traveled.
We know the velocity of sound to be 1500 meters per second through water; knowing this fact, the distance can easily be found by dividing velocity by the time it the echo takes to return. It shows up as a linear line graph. It has several lines converging with time. As things get closer the lines intersect, and as the distance between them increases, they diverge. The lines represent the different devices, which we have in the water. In our case, these lines show us the relative locations of the pinger, multi-corer, and the sea floor.
We know the velocity of sound to be 1500 meters per second through water; knowing this fact, the distance can easily be found by dividing velocity by the time it the echo takes to return. It shows up as a linear line graph. It has several lines converging with time. As things get closer the lines intersect, and as the distance between them increases, they diverge. The lines represent the different devices, which we have in the water. In our case, these lines show us the relative locations of the pinger, multi-corer, and the sea floor.
Before I continue, I should explain what it is we’re doing.
Simply said, we’re multi-coring; which is a fancy way of saying that we’re trying to take samples of dirt off the bottom of the ocean.
The device has an arrangement of four tubes along its bottom with legs that stabilize it. When it reaches the bottom, the tubes plunge into the mud and capture the sediment.
It just so happens that we’re doing this at a depth between 3.5 to 5 kilometers (2.8 miles on average) deep. We’re scooping up dirt, and in that dirt we’re looking for “black carbon” which is loosely defined as an in-complete combustion of biomass or a fossil fuel (K.Pohl).
Simply said, we’re multi-coring; which is a fancy way of saying that we’re trying to take samples of dirt off the bottom of the ocean.
The device has an arrangement of four tubes along its bottom with legs that stabilize it. When it reaches the bottom, the tubes plunge into the mud and capture the sediment.
It just so happens that we’re doing this at a depth between 3.5 to 5 kilometers (2.8 miles on average) deep. We’re scooping up dirt, and in that dirt we’re looking for “black carbon” which is loosely defined as an in-complete combustion of biomass or a fossil fuel (K.Pohl).
What a great experience! You do an excellent job of sharing your journey. Thanks. I hope BCC prepared you well for this work.
ReplyDelete