Monday, September 9, 2013

Science onboard R/V Thompson

Weather:
The clouds are back, but the air temperature is warm (mid- 60's); the seas are relatively calm.

Science Update:
Today's Objectives:
1) Retrieve Jason from dive J2-729 - check!
2) Deck operations: Deploy over the side of the ship an OBH (Ocean Bottom Hydrophone- used for detecting earthquakes )
3) Launch ROV Jason on dive J2-730 the "Pressure Dive" - 5 days on the ocean floor to collect pressure data on a circuit of 10 Pressure Benchmarks (green dots on map at right) - check!

Chemists from University of Washington prepare samples for the next Jason dive in the Main Lab.
Science on board
In addition to science completed during Jason-Medea dives, there is a substantial amount of research completed at the surface on the ship while at sea. The main lab (right) on R/V Thompson has sinks, fume hoods, making the lab well appointed for a range of research, including wet chemistry, biochemistry, and microbiology.

Samples that returned from the seafloor can be processed on board the ship and/or stored until further analytical facilities are available at researchers' home institutions. Before the next dive, sampling devices must be cleaned and prepared for new samples to be collected.

GTB (Gas-Tight Bottle) sample collection during dive J2-726 at Casper Vent in the Coquille Hydrothermal Vent Field.
Gas geochemist, Leigh Evans is able to prepare his samples with a vacuum extraction apparatus in the main lab. He loads gas-tight titanium sample bottles that collect gas samples from hydrothermal vent fluids. These sample bottles are rather remarkable, because they have to be able to hold the vent fluid samples at the same high pressure that exists at the bottom of the ocean until they are analyzed, in order to prevent the gases from escaping on their way to the surface.

The robotic arm on Jason can maneuver samples bottles from the payload basket on the front of Jason and set bottles in place over the vents. The finger-like digits on Jason's arm trigger the bottles to open and collect samples.
Leigh Evans in the main lab, preparing a gas-tight bottle for the next dive.

Once samples are returned to the surface, Leigh can quantify the gas concentrations in the fluids and then will repackage samples to be stored on board until we return to shore when they will be transported to analytical labs. Ultimately, Leigh will analyze the He (helium) isotopes of the hydrothermal fluids; gas chromatography will be used to analyze H2 (hydrogen gas), CH4 (methane) and CO2 (carbon dioxide) of the vent fluids.

Engineers Jeff Breedlove, Ben Rush, Mike Carpenter (L-R) prepare an acoustic modem in the main lab to be deployed by ROV Jason.



In addition to dedicated space for specific tasks, the main lab also has plenty of bench and floor space for preparing instruments and staging them to be deployed to the sea floor (at left).

Once the day's work is complete, the science team rotates through shifts in Jason's control van (see video below) or enjoys one of the notoriously delicious meals, watches a movie, heads off for a quick nap, or relaxes in the ship's library (also used for science team meetings), before the next work needs to be done!




Some of the science team at lunch; bunks and storage in a “stateroom”; science meeting in the library.
video