NeMO Net RAS

NeMO Net Remote Access Samplers (RAS)

top view image of RAS, click for full size

RAS (system A) being deployed at Virgin vent. Blue circles are the 48 chemical sample bottles. (click for full-size)

The NeMO Net RAS samplers deployed in July 2002 were placed in the ASHES vent field. System A is located at Virgin vent, a high-temperature, anhydrite chimney. System B is located in a nearby low-temperature diffuse vent, called Dave's vent. The two RAS will monitoring the chemistry and temperature of these vents over the next year.

Each instrument is capable of collecting 48 vent fluid and particle samples in a time-series. The system is a McLane 48-500 Remote Access Sampler, with hardware and software enhancements done at PMEL. Temperature measurements are made every 10 minutes. The sampler is programmed to take a water/particle sample once per week and collect chemical sensor data (pH and H2S) twice per week. The system can also be sent a command at any time via satellite to collect samples or send back temperature data. This interactivity will allow us to take samples quickly and at critical times, for example in response to any seismic or volcanic activity, long before any ship could get to the site. By having these instruments in place we hope to learn more about the dynamic early stages of such events.

For more information use the following links to NeMO Explorer:
Hydrothermal vents
Anhydrite chimneys
Diffuse vents
ASHES virtual reality site
Video clip of Virgin vent
NeMO at Axial Volcano

RAS images

			View of the BPR (lower left) and one of the RAS (upper right) fluid samplers on the deck of the R/V Thompson before deployment.

			ROPOS positions the titanium fluid collector over the Virgin high temperature vent. Shimmering water rises up and collects in the inverted funnel, where the RAS intake is located. The fluid is pumped through titanium and teflon tubing back to the sampler. This tripod tripod was designed to prevent the precipitation of anhydrite in the RAS fluid intake.

			RAS sampler on the bottom. The acoustic modem transducer is visible on the top, left of center. The 3 vertical white cylinders are pH buffers and acid sensors. The three horzontal cylinders contain the electronics and battery power.

			View of the titanium tripod over Virgin vent after the first deployment.

			2001 NeMO Net RAS at Cloud Vent on Axial Volcano. View 2001 RAS deployment movies: Small/MPEG - 0.9 Mb Large/MPEG - 2.5 Mb

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