JR224: Chemosynthetic life in the Antarctic


 JR224



Cruise diary


Thursday 22 January 2009
Location: East Scotia Ridge

The excitement starts!!

Today, the hunt for hydrothermal vents on the East Scotia Ridge has really started! We arrived on station very early this morning, over the northern part of the ridge, where 10 years ago Chris German from NOCS and Roy Livermore from BAS found evidence of hydrothermal plumes.

We have now started exploring the ridge. The first equipment we deployed was the CTD. This instrument is deployed on the side of the ship and lowered in the water column. All through its descent, the CTD measures constantly Conductivity, Temperature and Depth and the data can be seen on real time on a monitor in the ship's laboratory. The CTD also has 24 bottles that can take samples of water at different depths. The idea is to lower the CTD in the region where the plume was detected in 1999 and try to find the hydrothermal plume again.The plume has a different density, temperature and chemical composition than the surrounding water, so if the CTD goes through it, the temperature and conductivity will increase and the analyses of the water collected in the bottles will detect the chemicals from the hydrothermal fluid...The excitement started when we saw a signal in the CTD data there is something interesting down there!!

We then deployed BRIDGET and tow it up and down in the water column – a technique called tow-yo! – at a depth where we estimate the plume should be. BRIDGET also measures several characteristics of the water column and sends the data in real time to a computer in the lab. We look for any signals in the backscatter and transmission values, which indicate a higher presence of particles in the water. These signals, amongst others, will help us locate the hydrothermal plume and narrow down its origin on the seafloor: the location of the hydrothermal vent itself, most surely inhabited by great populations of exotic animals. So BRIDGET was deployed during the afternoon and has provided a long night of continuous excitement as we surveyed the ridge and detected 3 PLUMES!!!!!!!!!!!

We are now going to turn back and survey the same area in a parallel line to narrow down the location of the hydrothermal vents, before we deploy SHRIMP to try to get the first glimpses of the vents and their animals. It has been a fantastic day!


Waiting for results in the CTD lab

Launching the CTD

Launching BRIDGET

All eyes on the monitors in the lab as
BRIDGET reveals the presence of hydrothermal plumes


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