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Logbook
June 25, 1999

Contents:

• News from Thompson
• News from Wecoma
• Participant Perspective
• Logbook from Teacher at Sea
• Question/Answer from shore to sea

Science Report - Friday, June 25
Ships Location: 45 56.0/-129 58.9

Dave Butterfield and Julie Huber retrieving samples from the fluid sampler after Dive 485.

Last nights dive (485) collected the first samples with the vent fluid sampler at Marker 33 (a vigorous vent site in the middle of the 1998 lava flow). The initial results suggest that fluid samples are similar to those collected last summer at Marker 33. Some were so full of gases that they were bubbling at the surface. Many high-temperature microorganisms (hyperthermophiles) were cultured from the vent fluids at 90 degrees C (as they were last year here), but one was even cultured at 110 degrees C! That is 10 degrees above the temperature that water boils at sea level! And this organism is happy to grow in it! This is an exciting first for the NeMO Project. Last summer we didnt even try to culture microbes at temperatures that high! The temperature of the vent fluid that was sampled was only 63 degrees C (actually a few degrees higher than that measured last year at Marker 33), so obviously the temperatures are higher below the seafloor. These early results are a little surprising since vent sites at all the other eruption sites we have studied have cooled down and changed chemistry dramatically within the first year after the event. But Axial volcano seems to be maintaining its above average hydrothermal output. We will have to visit more vent sites to see if this pattern holds. Between ROPOS dives today we also collected additional rock cores and deployed another transponder net for navigating dives we will make in a few days to see how far south the 1998 eruption really extended on Axial volcanoes south rift zone.

Frustration is an inevitable part of Oceanography, because any time you put something over the side of a ship at sea, it may not work or you might never get it back. This is particularly true when you have something designed to work at the bottom of the ocean - perhaps the most challenging engineering environment on Earth due to the corrosive conditions and the

John Chadwick extracting rock chips from the wax cups at the bottom of the rock corer.

crushing pressure. The ROPOS remotely operated vehicle is no exception and since it has complex mechanical, electrical, and hydraulic systems, sometimes there are problems. When the vehicle is working well, it is truly spectacular. When the vehicle is having problems, it can be very frustrating. Unfortunately, today has been one of those frustrating days. The dive last night had to come back up after only 1 hour on the bottom due to a hydraulic leak. Today the ROPOS team spent much of the day trying to track down the problem and fixing it. Tonight ROPOS dove again (dive 486), but as soon as it got to the bottom, the hydraulic leak reappeared and the vehicle had to immediately head back to the surface and they will have to try to track down the problem again. Some days you bite the alligators. Some days the alligators bite you. Its well a bit frustrating. But we are, as always, looking forward to the next dive and the discoveries it may bring. In the meantime, there are more rock core samples (photo right) to collect.

Chief Scientist Dr. Ed Baker (right) reviews the distribution of operations over Axial Volcano with Drs. Dick Feely (left) and Joe Resing (center) in one of the Wecoma's labs. So far at Axial the Vents team has conducted eight "tow-yo" operations and 16 vertical CTD casts. These operations define the dispersal of hydrothermal plumes away from Axial Volcano, allowing the scientists to estimate the rate at which hydrothermal fluids are flowing from cracks in the floor of the caldera.

Vents scientists launch a CTD from the fantail of the Wecoma. The 1200 pound instrument and sampling package is lifted off the deck with the Wecoma's winch, then carried out beyond the ship's stern with the moveable A-frame overhead. The package is lowered some 1500 m (about 4500 ft) to within a few meters of the seafloor, continuously sampling the temperature, salinity, and optical turbidity of the water column. On the way back up, the plastic sample bottles are closed to return water samples to the scientists for detailed analysis.

Listing of all Science News postings

Jim Gendron

NOAA Vents Program

My name is Jim Gendron. I am an oceanographer with NOAA's Pacific Marine Environmental Laboratory in Seattle. I have been with the lab for 19 years. My main interest in the VENTS program is to help further the understanding of hydrothermal particulate matter. This includes trying to determine how they form, and their distribution and chemical makeup and evolution. I also have a strong interest in radon, a radioactive gas that is found in very high levels in the vents.

This work at Axial volcano is very exciting. I participated in the response cruise in February 1998, which was right after the original eruption. The samples that were collected then showed that very large particles had been blown high into the water column. When we visited Axial volcano last summer, the plumes over the volcano were reduced in volume and the average particle size was smaller. ROPOS did find lots of interesting activity on the bottom. So far this year the vent sites that we have visited seem to be more focused and at least one vent, somewhat warmer.

The main tools that we use to collect particulate matter with ROPOS are the fluid sampler that Dave Butterfield has developed and conventional Niskin samplers. The Niskins are PVC tubes that can collect about 5 liters of sample at once. The Niskins are then pressurized with nitrogen and the sample is pushed through a polycarbonate filter. We try to collect up to 500 micrograms per filter. The filters are then dried and when we return to the lab they are analyzed for 17 elements by X-ray fluorescence (XRF).

In general, eruptions such as the one at Axial volcano in 1998, release a very large amount of metals, especially iron, into the surrounding sea water. In addition, they remove a large amount of dissolved phosphate, which in the surface waters, is an important nutrient.

Listing of all Perspectives postings

Wecoma Teacher at Sea Log

Day 10, Friday 6/25/99

During the evening hours we completed our data collection at Axial Volcano caldera and moved to a new location. We are now located on the Cleft segment at the southern end of the Juan de Fuca ridge, almost due west of the homeport of our vessel, Newport, Oregon. Systematic studies of the hydrothermal vents on the Juan de Fuca Ridge originated here in 1980, only two years after the very first vents were discovered in 1977 on the East Pacific Rise. The northern Cleft segment, which we are studying today, has been studied every year since 1986 by the Vents Program. A "mega-plume" lava eruption in 1986 at this site produced great mounds of pillow lavas and a new vent field. This eruption also releases a "mega-plume" - enormous releases of hydrothermal fluid that rise a kilometer above the seafloor - the first ever observed in the ocean (image right, click for full size). The lava flows of the northern Cleft segment are distinctly younger than the flows found elsewhere on the segment. Scientists estimated them to be less than a few hundred years old.

We will be taking two tow-yos along this segment. The first tow will be almost twenty-seven nautical miles with a duration of over 18 hours. There has been evidence of a decrease of hydrothermal activities and plume discharge over this site, suggesting that the system is continuing to cool down.

Dr. Joe Resing has mounted the "Submersible System Used to Assess Vented Emissions" (SUAVE) on the CTD rosette to measure concentration of Mn (Manganese), FeII (Iron) and H2S (Hydrogen Sulfide) for comparison with data from previous years. This instrument reacts with sampled water to form colors specific to the elements we are looking for. The concentrations are measured by the intensity of the color. This method is known as the colorimetric technique. The SUAVE has its own "personality". It has a bright yellow frame with a multitude of tubes, detector LED's (Light Emitting Diodes) and 12 plastic baby bottles with colorful cartoon designs. Even with its humorous exterior the SUAVE has been a significant surveyor for the scientists.

While working on the fantail of the Wecoma we were visited by a young male Northern Fur Seal. He swam about our ship entertaining us with his antics. He jumped in and out of the swells with great speed occasionally giving us a look with his cute dog-like face.

The activities on board go on like clockwork with the crew and scientists focused on the tasks to be completed. The lab and bridge is bursting with activity continuously 24 hours a day.

It is exciting for me to continue to spot whale blows on the horizon. Today I added Humpback whales to my list of cetaceans documented. These were easily identified due to their bumpy rostrum, rorqual streaks, blowhole placement and dorsal fin. The largest of the two was near fifty ft. in length, while the smaller was between twenty five and thirty ft. I continued to search the horizon for additional sightings.

Check the NeMO site tomorrow.

Fair seas
Ms. Deck

Thompson Teacher at Sea Log

Teacher Log #6 6/25/99

The major component of Dive 485 was the collection of vent fluid using the specially designed Vent Fluid sampler. This device is designed to collect up to fourteen 800 ml containers of vent fluid from specifically targeted places within the vent fluid stream. This allows for a discrete sample at a known temperature. The sampler is built to fit the ROV just below the body and towards the front so the sampler is visible during the operation. The actual collecting probe is fitted to one of ROPOS arms for placement accuracy. The sampling operation during todays dive was successful.

When ROPOS is in action down along the ocean floor, many of the scientist and technicians are viewing the actions on monitors placed around the ships labs. During the ascent back to the ship, those with samples on the way to the surface begin preparation for necessary lab work to be done. Samples of vent fluids and biological materials are required for their research, so when these samples finally reach the deck, the sense of urgency takes over as the "shelf life" for these samples is quite limited. No sooner then it takes to tie off and secure ROPOS and its cage, samples are whisked away into the respected lab areas.

Andy Graham running gas chromatograph samples

Todays collection involved samples for a number of individuals. Andy Graham, a chemical oceanography technician from the University of Washington will be seeking to determine the amounts of methane and hydrogen in the vent ecosystem. Methane and hydrogen act as the major energy sources for life. Hell use an onboard gas chromatograph to determine the levels present in the vent water. Kevin Roe, a chemist from NOAAs Pacific Marine Environmental Laboratory in Seattle, will go about determining the amounts of hydrogen sulfide, ammonia and silica found in the fluids as well as calculating the pH and alkalinity. Leigh Evans (with NOAA/PMEL Newport, OR) will go about trying to determine the quantity of Helium isotopes in the fluids. He has an elaborate setup designed for extraction of specific gases. He'll talk more about it is his personal perspective perspective later on the cruise. Jim Gendron's (with NOAA/PMEL Seattle, WA) goal ( today's personal perspective) is to determine the chemical reactions going on in the sea water at specific distances directly above the vents. On the biological side of things, Julie Huber a Masters candidate from University of Washington along with U of W technician Sheryl Bolton, began the process of culturing the microbes from the fluid in hopes of learning about the diversity of the microbial population. Some samples were frozen in liquid nitrogen for transportation back to shore where more complex DNA studies can be used to help answer their questions.

Bill Chadwick and Susan Merle manning the ROPOS navigation center in the main ROPOS control station

While ROPOS is in action, a constant vigil is maintained on the navigation computer so as to know just where it is in relation to the bottom site, the cage and the ship. Three people work tirelessly on four hour shifts round the clock when a dive is in progress. Knowing the ROVs position is crucial to being able to direct it to the next target. Using four ocean transponders located 200 m from the bottom and one mounted on the cage, the pilot of ROPOS gets updated information regarding where he is. The bottom of the ocean is a very large place and it has no real road signs, so communication between the ROV and transponders is essential. Otherwise ROPOS would be flying blind down there. Bye for now.

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