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Perspectives at the End of NeMO99
Bob Embley-NeMO99 Chief Scientist

Heavy seas on the last days of the cruise prohibited any further dives and made the ride home a rock n' roll experience.

We're now steaming back to Astoria Oregon after another successful year at the NeMO site on the summit of Axial Volcano. Although the last dives at ASHES Vent field were compromised by the weather, we were able to retrieve some of the instruments and experiments that were deployed last year and to take an array of valuable samples. I'm writing this in my cabin as it rolls back and forth in 18 foot seas that are broadsiding us from the north. (photo right)

Overall, this year's cruise rivaled the success of NeMO98 and the scientific party will again have a full load of samples and data to analyze. The effects of the 1998 eruption are still apparent on the eastern side of the caldera where the lava flow was erupted. Venting continues in many places (e.g. Marker 33, Cloud, and Magnesia), whereas there has been reduction or cessation in others. Although the amount of visually apparent microbial activity (such as the white floc in the water column) has decreased, there continues to be concentrated"snowblower" activity at some vents (e.g. Magnesia Vent) and hyperthermophilic microbes were again found in abundance at most of the diffuse (low temperature) sites, (whose temperature is well below their optimal growth rate). These observations lead to the conclusion that there is still enhanced subsurface microbial growth more than a year and a half after the eruption.

We found the likely southern end of the lava flow about 6 kilometers south of the caldera lava along a spectacular fissure system that was followed for hundreds of meters. In some places the eruption was entirely contained in the 1 to 2 meter wide fissure. Eventually, it overflowed its fissure and erupted in the large mound of lava that we first saw last year. Farther north towards the caldera, the trace of the 1998 lava became more confused as the slightly older eruptions mixed with the 1998 lava. Active hydrothermal venting was only found on the summit of Axial, probably where the underlying zone of molten lava permanently resides. The summit area contains hydrothermal systems formed during several different volcanic or tectonic (earthquake generated) events, providing a natural laboratory for studying colonization and evolution of these unique chemosynthetic ecosystems.

One of the viewers from our WWW audience asked the question:
"What are we doing out here that will make a difference in people's daily lives?"
This is a good question, and I'd like to try and answer it on several levels. First of all, I believe that ocean floor research is one of the last frontiers of terrestrial exploration. We literally know more about what the surface of the moon or even Mars looks like than we do the floor of Earth's oceans. Hidden below the ocean's is the earth's largest volcanic system, the 60,000 km long Mid-Ocean Ridge. The ridge grows by the process of seafloor spreading, by which the earth is actually renewing its surface. Surprisingly, little is known about the actual processes that form this feature, because of the harsh conditions and remoteness of the deep ocean. Volcanic eruptions have to frequently occur along some portion of this ridge, but the only place that can actually be monitored is the small outlier of the ridge in the Northeast Pacific Ocean (because of the Navy's hydrophone net). Knowing when an eruption occurs allows scientists to study the processes that occur when molten rock meets chilled seawater on a giant scale. The chemical and biological processes that occur during and immediately following these events are of increasing interest because of the extremes of temperature and pressure associated with deepsea volcanism. Herein lies the promise of NeMO and other similar projects that seek to monitor active processes in the last frontier environment on earth. We will finally begin to visualize and understand the most active environments on the ocean floor as we can a critical estuary or a rain forest on land. Now is the time to do this, before we, in ignorance, destroy what may help us in the future. Earlier this year, Canada took an historic step in declaring that a major deep-sea vent field on the >Endeavour Ridge (about 120 miles north of Axial Volcano) was under study as a possible marine protected area. Most of the Mid-Ocean Ridge is in international waters and therefore not subject to national jurisdiction.

One of the goals of NeMO is a baseline of information that will aid future generations in understanding these environments. Such "basic" research many times leads to applications that could not be predicted at the time. The United States has invested in such basic research as a national policy for more than half a century, and it is apparent that it has paid back to society much more than its bottom line. In the case of NeMO, there may also be more immediate payoffs. The extremes of heat and pressure at the deep hot vent sites give rise to microbial life that may be quite different than anything in the terrestrial ecosystem. On this cruise, a microbe that can thrive at the very fringe of what life can survive at (110 C) was discovered at one of the vents formed following the eruption. Some such "extremophiles" have evolved to produce enzymes that are of great interest to the biotechnology industry. One of the premises of NeMO (based on earlier work) is that Axial Volcano is the best location for these studies because its high level of volcanic activity provides better access to these extreme environments. We all feel extremely pleased that all of the components came together so well, and that nature cooperated (with the eruption) to produce the wonderful natural laboratory within the caldera of Axial Volcano. This year we received a extra bonus when the Rumbleometer was successfully recovered from its lava imprisonment to (hopefully) yield new important data on seafloor eruptions.

By continuing the interdisciplinary study of processes at Axial, we begin to understand how the rest of the Mid-Ocean Ridge works and by inference how the planet reforms its surface.

Science Report - Monday, July 12
Ships Location: 45 56.1/130 00.7

Vents of the ASHES vent field. Top: Hell Vent (fluid at 290oC; bottom: Mushroom Vent with tube worms.

ROPOS dive 502 lasted through the night and came up around breakfast. The fluid sampler collected a full suite of samples at both high-temperature and diffuse vents (photos right) in the Ashes vent field, including 15 water samples and 15 filters for microbial and particulate studies. In addition, suction samples were taken of microbial mat, vent fauna, and iron oxide deposits around the vents. A temperature sensor deployed last summer was also retrieved. Around midday, ROPOS dive 503 returned to the Ashes vent field, this time with the biobox in order to retrieve bacterial traps, and temperature recorders deployed last year. Additional work in the vent field was planned, but the dive had to be ended early due to weather. The winds and seas have been building today and the winds are forecast to increase to 30-40 knots tonight, so it is unlikely that ROPOS will get back in the water before the Thompson has to head back to port at noon tomorrow. This evening the ship is securing all the water-tight doors, making sure everything is tied down, and no one is allowed outside on the weather decks in anticipation of heavy weather.

Science Report - Saturday, July 11
Ships Location: 45 56.0/130 00.8

"Chapstick corers" invented for dive 501 to collect volcanic glass chips.

ROPOS dive 501 successfully completed two major geological traverses across the 1998 lava flow and collected 14 rock samples with a combination of the manipulator arms, the suction sampler, and newly invented "chapstick corers" (which have a wax cup for collecting volcanic glass from the surface of rock, like the rock corer does that we lower from the ship, but these look like giant chapstick tubes and can be used by the ROPOS manipulator arm). (photo right) After ROPOS dive 501, three moorings with miniature temperature recorders (MTRs) and nephelometers (which measure the level of particulate matter from hydrothermal plumes) were deployed in the southern part of Axial caldera. These moorings will make continuous measurements at several heights above the seafloor to monitor the plumes over the vent sites during the next year. Everyone is suddenly vividly aware that we have less than 2 days left before the Thompson has to return to port. The remaining ROPOS dives will be at the ASHES vent field, in the southwestern part of the caldera. ASHES is another high-temperature vent site with several black-smoker chimneys that expel water at up to 348 degrees C (which is actually the boiling temperature for seawater at this depth!). ROPOS dive 502 is currently on the bottom at ASHES and will collect fluid samples at the vents and biological samples with the suction sampler.

Time-lapse camera deployed at Marker 33 for one year in 1998 and 1999, documenting the colonization of animals at the eruption site.

Science Report - Saturday, July 10
Ships Location: 45 55.2/129 59.6

After ROPOS dive 500 came up this morning, we recovered the navigation transponders that we had put down earlier in the cruise. ROPOS dive 501 then deployed the time lapse camera at Marker 33 where it will stay for another year, and then ROPOS started a series of geologic traverses to better define the extent of the 1998 lava flow just south of the area we mapped last year. We think some of the southern-most vent sites we have found (Marker 113, Joystick vent, and Bag City,) are actually located along the eruptive fissure of a very young, but pre-1998 lava flow. This young lava flow is difficult to distinguish from the 1998 lava, so we will be making careful traverses to map out the transitions from one lava flow to another. This will help us better constrain the volume of the 1998 eruption. Also, knowing the age of the lavas in which each vent is located is critical information for interpreting their chemistry and biology.

Science Report - Friday, July 9
Ships Location: 45 56.1/129 58.9

Deployment of the osmosampler at Magnesia Vent.

The objectives of ROPOS dive 499 were to collect additional fluid samples at several vent sites, deploy the OSMO sampler at Magnesia vent (photo right), and collect biological samples at some of the vent sites that exist in older lavas around the 1998 lava flow. These older sites are of interest to see if they are providing larvae for vent animals that are colonizing the new lava flow. Last year, different assemblages of species had colonized different vents on the new flow, even if they were nearby each other, which was a surprise. This year, the dominant species have spread over larger areas and there are more similarities between the new vents, but there are still some vents that have much different animals than others. This story of how vent animals colonize a patch of brand new seafloor will be an interesting puzzle to sort out in the years to come. Dive 499 had to be suspended when a hydraulic end cap burst, but it was quickly resumed after repairs (as dive 500, a milestone for ROPOS!) and will continue into the night.

Science Report - Thursday, July 8
Ships Location: 46 03.8/129 57.7

CASM vent with lush tubeworms and hydrothermal fluid venting from a chimney.

Dive 497 visited the CASM vent site to collect biological, sulfide, microbial mat, and vent fluid samples. The CASM site is located at the northern end of Axial's caldera where its north rift zone intersects the caldera. High temperature vent fluids have produced a line of sulfide chimneys in the bottom of a 10-meter wide fissure. Surrounding these chimneys are extensive areas of diffuse venting where tens of thousands of tubeworms grow in lush colonies that at times extend as far as you can see. This makes CASM a rather spectacular site for the biologists on board. CASM was the first high-temperature vent site visited by submersible on the Juan de Fuca Ridge back in 1983, and although it has not been visited many times since then, it appeared to be rejuvenated when ROPOS visited it last year. This site is of interest since the focus of the NeMO project is how hydrothermal venting and their biological communities change in response to volcanic events.

Later in dive 497, ROPOS moved further north along Axials north rift zone to where four extensometer instruments were deployed last year. (photo left) These instruments have measured the distance across the rift zone once a day since then to look for changes related to magma movements under the volcano. ROPOS had to return to the surface briefly during this operation, but then returned to finish the job on dive 498. ROPOS found each instrument on the bottom and moved each one to the elevator mooring, then released the mooring from its anchor so that it could recovered at the surface by the ship. We plan to download the data from the instruments, refurbish them, and then deploy them again for another year deployment.

Science Report - Wednesday, July 7
Ships Location: 46 00.9/130 01.5

ROPOS collected Imagenex data all night as dive 496 continued into the morning when it cut the anchor line holding down the rumbleometer.

Rumbleometer safely on deck of the Thompson after surviving a lava flow.

When it came to the surface, there were many lines hanging from the instrument from our past attempts to rescue it, and these had to be cleared before it could be brought on board. It was very satisfying to see the rumbleometer brought on board the ship - the final stage in its bizarre odyssey (photo right). It was interesting to examine the instrument on deck. The bottom side of several of the yellow plastic "hard hats" that protect the glass ball flotation had melted slightly (photo below left) and had chips of basalt glass embedded in them, which happened when 1998 lava flowed under the instrument. But overall, it is amazing that the instrument appears to be in pretty good shape despite having been trapped in a lava flow! This is apparently because the temperature at the bottom of the ocean is just above freezing (2 degrees C), basically like an ice bath, and there is an unlimited supply of that cold water.

Slight melting of the Rumbleometer's floatation.

When molten lava erupts into this cold seawater, it immediately starts forming a crust on its upper surface, and once the solid crust grows thick enough it becomes a good insulator, so that the solid crust of an active lava flow is much cooler than its molten interior. This is how the rumbleometer instrument could have survived a close encounter with the 1998 lava flow without being completely cooked (as it undoubtedly would have if the same thing happened on land)! The data from the instrument will not be downloaded until it is returned to Seattle.

This evening, ROPOS went back in the water for dive 497, this time on Axial's north rift zone to recover and deploy acoustic extensometer instruments with the elevator, and then to visit CASM, a high-temperature vent site at the northern end of the caldera, for biological and slurp sampling and to recover temperature probes deployed there last year.

Science Report - Tuesday, July 6
Ships Location: 45 55.9/129 59.0

From top to bottom: Rumbleometer stuck in lava flow; then ROPOS attaching lines for recovery attempt; Rumbleometer's anchor remains in lava flow; Instrument floating free for recovery!

Todays ROPOS dive (496) was devoted to an attempt to recover the Rumbleometer instrument that was caught in the 1998 lava flow. This instrument package is full of sensors to monitor volcanic events, and since it was located at ground zero for the 1998 eruption, it likely has some fascinating data on board. Consequently, we were anxious to try and rescue it again this summer. Over the winter, the engineers at NOAA/PMEL in Seattle who built the instrument devised a plan with the ROPOS group to attempt to extract it from the lava flow. The plan involved pulling upward with the ROPOS cage from the edge of the instrument, instead of from the center to give more leverage, and to rig the cage so we could pull with more force than we could last summer (10,000 pounds, instead of 2,000 pounds last year). The process of rigging the pulling lines from the Rumbleometer to the cage was quite involved and had to be done extremely carefully, and every step completed was followed by cheers from on-lookers in the ROPOS control room. Once everything was in place, the ROPOS cage began to pull upward, the tension on the line increased, and then went slack. Something had given way. Was it the instrument breaking free of the lava, or one the lines breaking? No one knew until ROPOS descended back down to the bottom and approached the site where the Rumbleometer had been. All that was left was the Rumbleometers anchor - the instrument had been pulled out of the lava! Last summer we had attached a separate line and anchor to the Rumbleometer so that if we did manage to release it from the lava, that it would not immediately float up and crash into the ROPOS cage. The Rumbleometer is now floating 50 m above the bottom on this anchor line, ready to be cut free by ROPOS tomorrow morning at first light. Once we get the instrument on board, this will stand as one of the most remarkable rescues of an oceanographic instrument, ever!

Science update:

Not wanting to slight the little guys, in this case microbes, we wanted to highlight one of the other new breakthroughs on this cruise...

Hunting for High Temperature Microbes

One of the best things about being a hydrothermal vent microbiologist is hunting for exciting microbes (photo right) that push the limits of life by surviving at environmental extremes such as high temperature and pressure. Our lab at the University of Washington, headed up by Dr. John Baross, is always in search of high temperature microorganisms, referred to as hyperthermophilic archaea. These are the most heat-loving of all known microorganisms, and all have temperature optima above 80 C. Because the surface of early Earth was likely much hotter than it is now, many scientists believe that these hyperthermophiles may have been the earliest life forms on earth. By studying these microbes, then, we can peer into the past, as well as into the possibility of life in the subsurface biosphere existing below the seafloor. The hard part, though, is catching the bugs. It takes a lot of luck to hunt them down, but a little preparation doesn't hurt either.

Before going to sea, I mixed up a wide array of nutritional media to try to mimic the natural environment of the subsurface seafloor. Because most high temperature archaea have been found to metabolize sulfur in some way, much of our media collection includes elemental sulfur, which is formed from geothermal hydrogen sulfide (see discussion in today's perspective). Additionally, most of these hyperthermophiles are obligate anaerobes, meaning they cannot grow in the presence of oxygen. When a sample comes on deck from the volcanic fluids from Axial, we inject some of this fluid into our anaerobic test tubes, careful to avoid any contamination by oxygen or other substances that may prove deadly to these microbes. We then place our tubes in incubator ovens set at different temperatures. (photo left) We commonly culture microbes at 55 C (referred to as thermophiles) and 90 C (hyperthermophiles). Every once in awhile, though, we try to push the temperature limit by incubating above 100 C. Currently, the highest known upper temperature limit for growth of a living organism is 113 C by a sulfur-dependent hyperthermophilic Archaea called Pyrolobus.

Two weeks ago, we got very lucky in our little ship-bound lab and managed to find a positive culture tube happily growing above 100 C. This microbe, growing anaerobically with elemental sulfur, was isolated from ~70 C fluid at Marker 33, a well-studied site on the new lava flow here at Axial. The fact that we have found a microbe (or group of microbes) growing at such a high temperature, yet isolated from fluids much below its temperature of growth, strongly suggests that there is a hotter subsurface environment that these microorganisms are growing and thriving in, perhaps hundreds of meters below the seafloor. It is not until a perturbation to the system occurs that these fluids make it to the seafloor, though, so the recent eruption here at Axial makes it an ideal study site for collecting these fluids and searching for subsurface microorganisms. By studying this exciting microbe, we hope to learn more about the metabolic wonders of life at high temperature and what limits life. Additionally, we will gain important clues about the deep subsurface and early environments here on earth, perhaps allowing us to speculate beyond our own planet to the possibility of life on other planets and moons. The hunt continues...

Science Report - Sunday, July 4
Ships Location: 45 55.9/129 58.8

New lava flow at the bottom of the fissure, southern extent of 1998 eruption. (Dive 494)

Last summer, we spent most of our time mapping and sampling the northern 3 km of the 1998 lava flow, and we confirmed that a depth change in a bathymetric resurvey located 5 km further south along Axial's south rift zone was a thick flow of 1998 lava, but we never had the chance to find out if these two eruptive areas were connected or not. The primary objective for ROPOS dive 492 was to traverse this area in between, to determine the extent of the 1998 lava flow and any related hydrothermal vent areas. This task ended up occupying three successive dives (492, 493 and 494) because the first two were terminated early due to problems with the ROPOS tether. We found that the 1998 lava flow is more or less continuous for a distance of 10 km, from the caldera southward along the south rift zone. The lava flow varies in width along this distance, but the dike (the magma-filled crack) that intruded into the rift during the earthquake swarm in January 1998 erupted along most of this length. In fact, we could actually see the dike and eruptive vent in several places. (photo above left) It first appeared in the south as a crack about 1.5 meters wide with new lava in the bottom, and as we traveled north along it, the lava gradually overflowed the crack and turned into a wider and wider flow. Some spectacular geology! ROPOS is already back in the water this evening for dive 495, which will focus on fluid sampling at the hydrothermal vents that were discovered on dive 492.

Science update...

Dive 493 in progress at southern extent of 1998 lava flow. Photo shows new lava flowing onto the old lava (old lava in lower left corner).

We are in the middle of an exciting dive where we have just discovered the area of the southern lava flow. We found a fissure that may be the top of a dike that fed the 1998 lava flow. There is new lava in the fissure! Stay tuned for a full update tomorrow!

Note: Scientists are very busy during this Dive and can not send a full report at this time. Evidently they have made some very exciting discoveries which they will report on in the next few days.
NeMO Webmaster

Chief Scientist's Weekly Report

Gelatinous masses (bag creatures) at a new vent (Bag City) discovered by ROPOS dive 491.

In many respects, today was the high-water mark of the cruise to date. This morning we confirmed that a line of venting associated with the 1998 eruption extended more than a kilometer south of the area mapped and sampled last year. These two new vents line up with the trend of the south rift zone of Axial Volcano and probably trace the path that the dike took as it was injected into and south along the rift. One of these vents, named "Bag City", (photo right) because of the high density of gelatinous masses of microbial origin, had the most dense colonies of new tubeworms yet seen on the 1998 lavas. The other vent on the new lavas had a high production of white floc similar to the vents at the northern end of the lava flow (e.g., Magnesia Vent). Collections of the animals found at these vents may answer many questions about the stages of colonization at new seafloor hydrothermal sites. Of particular interest in this regard was the possible sighting and sampling of a class of worms known as Nemerteans. These were found in large quantities at the CoAxial eruption site just north of Axial Volcano, but so far have not been found on the summit of Axial. How such animals find new vents and why they (apparently) disappear from the population after a period of time is not known. An older vent (on older lavas) was also sampled during today's dive. In contrast to the new vents, this site had beds of small clams, which probably is one of the last groups of animals to colonize a vent site. Their shells have known growth rates, so they can be used to date the (minimal) age of a vent. The location of this vent several hundred meters west of the line of new vents suggests that it represents the trace of an older crack, probably from a previous volcanic or tectonic event on the summit of Axial Voclano.

For several days, we have been waiting for the weather to calm down enough to retrieve the elevator (photo left). Several postponements arose from the concern that the wave surge would dislodge some of the samples and/or instruments and they would be washed out of the elevator at the surface. During the late afternoon, the command was sent from the surface to release the elevator from the seafloor with its cargo of instruments and samples. The personnel of the T. G. Thompson did a magnificent job in recovering the package in a combined small boat and ship recovery in less than optimal conditions.

We have made much progress in the past week on NeMO99 with several long and very successful dives. Most of the instruments deployed last year have been recovered and many of the key samples for the various disciplines have been successfully recovered. The hydrothermal system that arose from the 1998 dike injection and eruption is still vigorous, and it appears that we will be able to continue productive studies of its chemical and biological processes well into the future.

Science Report - Thursday, July 1
Ships Location: 45 54.2/129 55.2

We set a new record for ROPOS bottom time during dive 491 (38 hours)! Highlights of dive 491 included lots of samples with the slurp sampler, recovering instruments into the elevator, recovering bacterial traps deployed last summer, biological samples at a number of vent sites, and scanning sonar mapping. One interesting development during the dive was the realization that a vent site that we visited on dive 488 and had thought was new (located near the northern end of the 1998 lava flow near Milky vent), was actually Magnesia vent (photo right), which we had sampled last year. The reason we had thought it was new was partly because one navigation transponder was not working properly on dive 488 and our positions were offset, and also because the vent now looks very different from how it appeared last year. Last summer, Magnesia vent had milky-looking fluid venting with very fine white particles entrained in the fluid. This year, large white floc particles are coming out of the vent (like at other "snowblower" vents), but so much floc is coming out and settling to the bottom that the surrounding area looks like a snowy winter scene. A big change from last year.

ROPOS came back on deck this morning and we had hoped to recover the elevator mooring and be back in the water this afternoon, but the wind and seas have been building since yesterday and have caused the elevator recovery and the dive to be postponed. More rock cores from the south rift zone will be collected, and the samples and data collected during dive 491 will be processed in the meantime.

Science Report - Wednesday, June 30
Ships Location: 45 56.3/129 59.1

Biobox being transferred to the elevator to bring the samples up to the ship. (Dive 491, 1999)

ROPOS went in the water at 6:30 pm last night (dive 491), and after 23 hours on the bottom, the end of the dive is still not in sight! The NeMO scientists are getting as much out of this dive as possible, since as we have seen, you never know which way your luck is going to turn at sea. In the process, we may break the ROPOS record of bottom time on a single dive (currently 28 hours, set during NeMO98 last year), since the current plan is to bring it up tomorrow morning. On this dive, ROPOS is collecting biological and slurp samples at all the main vent sites in the northern part of the 1998 lava flow, recovering instruments, and collecting scanning sonar bathymetry. We plan to try and recover the elevator mooring in the morning (weather permitting). Everyone is happy to see that ROPOS is back at work on the bottom.

Science Report - Tuesday, June 29
Ships Location: 45 55.9/129 58.9

Keith Sheperd and Craig Elder working on ROPOS before dive 491.

We had a couple more unsuccessful dive attempts since yesterday (dives 489 and 490), interspersed with a lot of troubleshooting on deck by the ROPOS engineers, but ROPOS is now finally on the bottom again (dive 491) and the vehicle appears trouble-free. (Big sigh of relief!). Our objectives for this dive are still to recover instruments, collect biological samples, and expand our Imagenex sonar survey of the northern part of the eruption site. More on dive 491 tomorrow

Science Report - Monday, June 28
Ships Location: 45 51.1/129 54.1

Photo from dive 488 of Cloud Vent area. Pictured are bacterial traps amongst a new species of scale worms.

Despite the long and successful dive we had yesterday, there were indications that the vehicle was still having problems with its hydraulic system, and so to get to the bottom of the problem once and for all, the ROPOS engineers decided to work on the vehicle on deck most of today. Our science operations today included rock coring to sample lavas from Axials south rift zone and we took the opportunity to make a second calibration of the transponders we deployed two days ago, since our first one had some problems. Tonight ROPOS is preparing for dive 489, which will hopefully be another long one to recover instruments, collect biological samples, and expand our Imagenex sonar survey of the eruption site.

Chief Scientist's Weekly Report 6-27

This has been a great day out here at Axial Volcano. Were just now recovering the ROPOS after working 19 hours on the bottom. During this dive, we were able to accomplish much of the sampling we have strived to do over the last few days. Between the new and improved Vent Fluid Sampler and the Suction sampler, more than 30 vent fluid and biological samples were taken at several locations. These samples will provide critical material for analysis for most of the investigators on board and is probably a record for samples taken during a single dive. We also learned a lot about the "state" of the system. Most of the venting is now concentrated around the Marker 33 and Cloud Vent (photo above) sites, which may have elevated heat fluxes relative to last year. In fact, we only found one significant vent at the northern end of the system, although it was a very interesting one. This vent, which was in the vicinity of a series of vents characterized by their milky color last year ( Milky, Magnesia etc.), was now emitting a steady cloud of large white flocs (photo right and calendar photo of the day) which covered the surrounding rocks with a blanket of "snow" and brought to mind one of those "Christmas scenes in a glass" after theyve been shaken up. What we are probably witnessing at this site is the late stage of a subsurface microbial community that is producing large quantities of sulfurous material which they make from metabolizing the dissolved hydrogen sulfide in the fluids. This material is produced in sufficient quantity and rapidly enough to produce a steady stream of this material. This probably requires a special balance of a high hydrogen sulfide concentration, availability of subsurface cavities, and a relatively slow amount of flow into the cavity.

We were heading back to the Marker 33 site to recover the rest of the instruments (into the elevator) when the ROPOS team determined that the vehicle had to return to the surface for maintenance. It certainly served the scientists well today.

News from the microbiology lab on board was very intriguing and potentially very exciting. Some of the cultures made from samples taken at Marker 33 continued to grow at temperatures in excess of 90 Centigrade, which is very unusual. We await further word on this from microbiologists Julie Huber and Sheryl Bolton.

We hope to begin a very ambitious dive early in the morning that will likely last through most of the day.

Science Report - Saturday, June 26
Ships Location: 45 55.9/129 59.0

Deployment of the range meter for calibrating the transponders used for ROV navigation underwater.

We had more problems with hydraulic leaks on ROPOS dive 487, early this morning, but the ROPOS engineers are now confident they have found and corrected the problem. One of the lines that drained the hydraulic system was kinked and so pressure would build up and rupture seals elsewhere in the system. Before today, they were only correcting those ruptures, but not the underlying cause. ROPOS is now on its way down for dive 488, and hopefully will get to stay down as long as we want it to this time. While ROPOS was on deck today we calibrated the navigation transponders we deployed yesterday, which is the process you have to go through in order to precisely locate them on the seafloor before you can use them for navigation. On this dive, well be trying to visit some of the other vent sites on the 1998 lava flow that we saw last summer to collect vent fluid samples, biological samples, recover OSMO samplers, and collect more Imagenex sonar data to expand our high-resolution map of the lava flow. Our hopes are high for a long and productive dive.

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.

Science Report - Thursday, June 24
Ships Location: 45 45.2/-130 08.3

ROPOS returned to the Marker 33 area early today for dive 484. Bacterial traps (right) that were left at the vent site since last summer were recovered and new traps put in place for the next year. The bacteria that have colonized these traps will have their DNA analyzed to find out what organisms are living in these seafloor hot springs. An extensive biosphere of primitive microorganisms is believed to live in high temperature environments below the seafloor (at temperatures even above the boiling point of water at sea level!). This deep hot biosphere is brought to the surface and made accessible to sampling by submarine volcanic eruptions. This is a lot of what motivates the research in the NeMO Program - the interactions between volcanism, hydrothermal chemistry, and biology.

ROPOS also visited Cloud vent for the first time this trip and found that it was also still vigorously venting and had been much more extensively colonized by vent animals than we saw last summer (including scale worms, tubeworms, and the new species of scale worm discovered last year). In fact, there were so many scale worms (left) around Cloud vent that it looked like the lava rocks had chickenpox! At the end of the dive the time-lapse camera that had been at Marker 33 for a year was recovered, and all signs suggest that it worked (though the film will not be developed until after the cruise). Our visits to Marker 33 and Cloud vent are very encouraging because they show that the venting in the 1998 lava flow has not diminished significantly, and yet many changes have taken place since last year. The story that is unfolding is an interesting one, but we are only at the beginning - there should be many more details to come.

Science Report - Wednesday, June 23
Ships Location: 45 41.2/-130 04.4

ROPOS made its first visit to the bottom early this morning (dive 483). We dove on the most vigorous vent site that we had found last year (Marker 33) where we had deployed instruments, samplers, and a time-lapse camera. What we found was that the site is still venting strongly, and had been colonized by new animals since last summer. In fact, a clump of tubeworms were right in front of the time-lapse camera, which took a photo every 30 hours over the last year, so it should have recorded their colonization and growth. ROPOS also recovered an OSMO sampler (photo left), a temperature recorder, and several bacteria traps that had been at the vent since last summer, but the recovery of the time-lapse camera will wait until the next dive. We also took several samples at the vent with the suction sampler for chemical and biological studies. The next dive will go back to Marker 33 to recover and redeploy more experiments there before exploring more sites on the 1998 lava flow.

Science Report - Tuesday, June 22
Ships Location: 45 56.0/-129 58.7

The Thompson is now on station over the 1998 lava flow at Axial Volcano. We arrived here yesterday evening, and the first task was to turn on the navigation transponders that we left behind here last summer. Since then, ROPOS has gotten wet twice, but we havent seen the bottom yet. This is because of complications related to removing air from ROPOSs hydraulic system, and communication problems with the fluid sampler. Neither of these are serious and will be worked out soon. This is fairly typical for an oceanographic research cruise. The ROPOS system is very complex and it often takes a day or two to work out problems before things get going smoothly. Basically, if anything is going to go wrong, it usually happens in the first few days. In the meantime, we have completed one CTD cast (above photo) (to get background water samples) and four rock cores (photo right) (to collect basalt samples on Axials south rift zone). We were also visited by a group of Dalls porpoises (calendar photo) today. Right now ROPOS is being prepared for another dive, that will concentrate on recovering many of the instruments and samplers that have been deployed since last year. The science party is anxious to see how the 1998 lava flow may have changed. Will the vents we saw last year still be active? If so, will their chemistry have changed? Will the animals communities be different at the vents? Stay tuned!

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.

After a week of solid work here at Axial we have a good idea of the sources and fate of the hydrothermal venting initiated by the 1998 eruption. As in the summer of 1998, the principal venting source remains the new lava field, with a minor contribution from the long-lasting ASHES site. Both the optical and temperature intensity of the plume are comparable to that found last year, indicating little decline in the hydrothermal activity. The horizontal extent of the plume is also similar to 1998. Thus the NeMO site appears headed for a long period of substantial discharge. This trend is in sharp contrast to the previous two eruptions, at CoAxial and Gorda Ridge, both of which experienced a significant decline after 18 months.

Our plume mapping and sampling has defined a narrow and intense plume being advected primarily to the southwest, out of the open end of the caldera. The plume bends around the caldera and streams to the west, with the core only a few km wide. We suspect that the currents are being steered by the bathymetry. The current records for last year that we recovered on this cruise will let us test that hypothesis, and should provide a basis for a good estimate of the heat and chemical flux from the new eruption site.

In addition to the plume work, we have successfully recovered all 9 moorings from last year, and deployed 6 new ones in their place. The Thomas Thompson will deploy our other 3 moorings after their work with ROPOS is completed. New this year on the moorings are 14 optical-temperature sensors--"mini MAPRs" that will monitor the plume more clearly than can temperature alone. Also new on the moorings are 2 "osmosamplers" built by researchers from MBARI. They will continuously sample plume waters into very small diameter tubes, which will be analyzed after recovery next year.

(image shows cumulation of plume studies at Cleft from 1986-97)
We have about 2 more day's work here, after which we will proceed south to the Cleft segment for 3 days to continue our 15 yr time series at those venting sites. Everyone on board has been working very long hours and accomplishing more than they anticipated.

That's the news from Wecoma. We'll arrive in Newport the morning of the 29th. Cheers, Ed Baker

Photo of Wecoma taken from R/V Thompson on 6/22/99 at Axial Volcano site.

Not available, see Wecoma teacher's log.

Not available, see Wecoma teacher's log.

This morning (Sat) we are CTD towing the east wall of the caldera and will be working in this area for a few days, trying to get as much done as possible before the Thomas Thompson arrives.

Friday was devoted to mooring recovery, collecting all 9 moorings in about 12 hrs--quite a busy day! All equipment was recovered successfully. Moorings at Sonne showed heavy corrosion and Fe encrustation. One of the screws holding the LSS bracket to a MAPR pressure case was corroded to the size of a pin.

Weather has been uncommonly good, with little wind and sea, so we've accomplished a lot. Wecoma arrived Thursday evening and made two CTD casts over the new lava flow. Hydrothermal activity is still plentiful, with optical anomalies comparable to last year. Visual inspection of the filters suggests most of the particles are sulfur/biogenic, not metal sulfides. Several people have said they can smell sulfur impregnated in the mooring lines we've collected. Height of the maximum plume horizon seems to be 50-100 m less than last year, suggesting a diminishment in the heat flux.

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