NeMO August 30, 2003

Logbook: August 30, 2003

The NeMO Net buoy is deployed by the PMEL engineers and Thompson crew. In full size image (click), pictured left to right are Jon Shanley (PMEL) and Thompson Captain Phil Smith

45°55.2. N, 129° 58.8' W
Air temperature 62°F, 1530 PST

Dive R734 ended today at 0945 PST after a record-breaking 44+ hours in the water. Following the dive, the NeMO Net buoy was successfully deployed, which communicates with monitoring instruments on the seafloor and then sends data back to shore in near real-time. At present the PMEL engineers are recovering two moorings which were deployed last summer with temperature recorders, current meters, and chemical sensors to monitor hydrothermal plumes. ROPOS is scheduled back in the water at 1900 PST.

Cruise Calendar

Aug/Sep 2003

S M T W T F S

24 25 26 27 28 29 30

31 1 2 3 4 5 6

7 8 9 10 1111. 12 13

Click on day to view other logbook entries.

<- Back | Forward->

Bill Hanshumaker, educator at sea, archives back-deck operations with his digital camera.

Teacher's Report
Bill Hanshumaker, Educator at Sea

Last night's sunset was spectacular. The waxing crescent moon followed the sun as it set in the west, while a brilliant red planet named for the god of war rose from the east. Only Neanderthal man 60,000 years ago has seen Mars at this magnitude!

We removed two recording temperature probes (HOBO's) that were deployed last year at Vixen vent. These probes take a reading every 30 minutes to monitor any temperature change that may occur through changes in magma or seawater circulation. Though the probes are capable of recording temperature more frequently, it would dramatically shorten the duration of recording. Two new probes were deployed in order to continue monitoring this site during the coming year. The current temperature at this vent is so high, no living organisms were observed on the chimney, although heat-loving sulfide worms were thriving at the base of the vent.

Image of the base of Vixen anhydrite vent. The chimney toppled when the 2002 Hobo temperature probes were recovered. Pictured here are the Hobo probes that will monitor the vent temperature for the next year .

Vixen is an anhydrite vent. The white chimney was very fragile and fell apart at ROPOS's first touch. But the chimney naturally collapses under it own weight, leaving a resulting mound for the next chimney to build upon. The anhydrite vent water is normally clear, unlike the black smokers. This is because the main chemical product of an anhydrite vent chimney is calcium sulfate, unlike the copper, iron and zinc sulfides found in the black smoker chimneys.

At 9:44 a.m. PST, after 44 hours and 44 minutes submerged, ROPOS was brought back on deck. This was the longest dive in ROPOS's illustrious career. Scientists impatiently waited until the crew safely secured her to the deck. Biological specimens that were collected on Axial can not survive long at our relatively high temperature and low atmospheric pressure.

Image of Marker-33 vent on the 98 lava flow. Tubeworms and a spider crab are the most visible biota. The yellow line is connected to a MTR temperature probe that was deployed on the first dive of 2003.

Sampling jars were quickly taken to the shipboard labs and coolers. The HOBOs were separated from the animals in the biobox and taken to the lab to download the temperature record. Biologists began identifying and sorting the vent creatures. A few animals were immediately put into small chambers where their accustomed pressure was artificially restored. These animals will be subjects for shipboard experimentation. Meanwhile, ROPOS technicians crawled over every inch of her superstructure, preparing her for re-deployment later this evening. Shipboard time is precious, so we are using this time between ROPOS dives to deploy the NeMO Net buoy and recover two moorings that have been recording temperature, light scattering and currents over the past year.