Tuesday, July 20, 2010

Examining some rocks recovered from 3000 meters.
Some granite and basalt recovered from the box corer.

Michael deploying a late night cast in search of some zooplankton.

Throughout the cruise I have been running experiments on photodecomposition of methylmercury in seawater. The samples in the left incubation chamber are covered in foil to block light and observe decomposition by microbiology while the samples in the right chamber are exposed to study decomposition by sunlight. Both chambers recieve a constant supply of fresh seawater in order to maintain the same temperature conditions as the ocean surface.

Monday, July 19, 2010

Flux Core Experiment

Me placing a flux core in the incubation chamber.
I'd also like to give a shout-out to Mr. Geyer! :)

Currently on the cruise, my research involves sediment flux cores. The box corer is sent down at a pre-determined depth and is used to collect sediment and pore water. Afterward, a long core tube is used to collect the sediment and overlying seawater and capped off to create a flux core. At each station, my job is to obtain three of these flux cores, filter and collect the seawater from each and measure the height of initial water column before placing them in an incubation chamber. After the cores have incubated for a 6 hour period, I again filter and collect the water and measure the height of the remaining water column for each before filling the core with fresh seawater previously collected at that station. Then, the cores are placed in the incubation chamber again and the same process is repeated for a 12 hour incubation period and an 18 hour incubation period. The ultimate goal of my research is to find out how much mercury is entering the seawater from the sediment after each incubation period. This will allow us to hopefully disprove the hypothesis that much of the mercury found in the ocean comes from the deep sea sediment. Recently, we were able to obtain sediment from a depth of 3,200 meters for the flux cores!!!
-Deepthi =)

Sunday, July 18, 2010

Chad works with his sediment cores in an oxygen free glove box.
Deepthi hard at work!