July 11, 2010 Sunday
Location: West of the Azores
Coordinates Lat / Lon: 37*50.9975' / 30*17.5978
Air Temp: 22*C / 71.6*F
Sea Surface Temp (SST): 22.95*C /73.31*F
Salinity: 35.69 psu
Depth: 2032 m
It is with very dry hands that I sit down to create today's blog . Why? They're dry from touching all kinds of sediment pulled up in cores from beneath the ocean floor. With each sample, there were "oohs" and "aaahs" and comments like this one from Dr. Ricardo De Pol-Holz of Univ of CA Irvine,"This sediment is amazing stuff! It's perfect pelagic ooze!".
Chief Scientist, Lloyd Keigwin, is pictured above with some of the "bug"(foram)-filled ooze. The coring crews were excited as the cores were executed beautifully. We smoothed the sediments between our fingers and thumbs, feeling for forams. Yes you can really feel them! They feel, well, like grit - and sometimes you can see them!
Collecting core samples from the ocean floor is a very expensive and challenging endeavor. Technologies, such as sonar and satellites, that allow for remote sensing of the ocean floor are improving all the time. But at this point, researchers still need to have the sediments from the bottom of the ocean brought up to the surface to study them thoroughly. The concept of "coring" is pretty simple. Coring apparatuses are long tubes that are dropped from the research ship down to the ocean floor. They range in length, diameter and material and are designed to meet the sampling needs of particular disciplines within the ocean sciences.
Keigwin and his team of scientists are using three main coring technologies: Long Core, Giant Gravity Core, and Multi Core. While the coring tools vary in their specifics, they each function like a drinking straw.
Have you ever put a drinking straw into a cup of liquid then placed your finger on top of the straw, covering the hole and then pulled the straw out of the liquid? The straw stays full of the liquid as long as you keep your finger pressed firmly over the top opening. I think it's my favorite way to drink chocolate milk. If you haven't tried it - give it a go! And you'll be modeling ocean coring.
Each corer is released from the research boat and allowed fall (rate is controlled by hugely powerful winches, pictured right). As the corer nears the seabed, the coring crew can let the corer fall faster, to increase the chances of it making the deepest, most complete core possible. The corer cuts into the seafloor, jamming ocean floor sediments into the corer pipe. Each corer has a device that acts like a finger on a drinking straw so that when the core is
brought back up after having been filled with oceanfloor sediment, it brings all the sediments along with it. The corer is then brought onto the ship where the plastic liners full of sediment are carefully removed, as you see Chris Moser and Paul Walczak, both from OSU, doing here. After removal, core segments are labeled and sent to the onboard lab for initial testing.
In the midst of the coring activities the captain announced that a fishing line was caught in one of the propellers. All kinds of ideas
were offered but it wasn't until an underwater camera was attached to a stick and lowered into the water that we had a clear idea of just how tangled the line was. It was decided a diver with flippers and snorkel would be necessary to untangle the knot. However, waste food had just been dumped from the
kitchen. It "chummed" the water - and guess who would be attracted to all that food! So we steamed a mile away and brave crewmen dove in and untangled the prop - never a
dull moment at sea!
Here's Joe Bastoni, Third Engineer, with the knot!