What's Happening Today - Nov. 13

 Happiness is a working sonar! Mark Rognstad's and Bob Waters' hard work yesterday fixing the sonar electronics paid off - big time. In the wee hours of this morning the DSOG and Atlantis crew put the DSL-120A sonar back together and we deployed it hoping to finish our remaining sonar survey tracks. The sonar is now working better than ever. The data are excellent and we're seeing the detailed volcanic geology and structure of the west flank of the East Pacific Rise (EPR) axis unfold before our eyes on the computer monitors on board R/V Atlantis.

So, we're merrily rolling along at 1.4 knots speed, headed south on our 4th sonar line. In the meantime, the HMRG team has produced maps of initial mosaiced images of our first sonar survey on the east side of the axis ­ they look great. We're tweaking the navigation, but already we've been speculating on how the different features were created and their meaning for how the ocean crust is formed at the EPR axis. Tomoko Kurokawa, a graduate student of Margo Edwards at the U. of Hawaii is helping produce the sonar images. She will be using them for some of her thesis research. Her thoughts on being at sea are typed below.

Life on board ship is great. Everyone seems like family now, and the ping-pong tournament is about to begin so practice sessions take place at all hours of the day and night. Tonight's dinner was a standout. Roast duck with orange sauce, rice pilaf, broccoli, beans, home-baked bread and, to top it off, blueberry cheesecake. Hats off to our terrific Galley Crew ­ Carl, Jay and Linda.

Big news today ­ John Cawley won this week's football pool ­ way to go John!

Best Regards,
Dan Fornari

On this cruise I am processing the data from the DSL-120A sonar for the first time. DSL-120A is towed behind the ship using a fiber optic cable. The sonar fish is towed at the altitude of 75-125 meters above the seafloor. For this survey we have had about 3000 meters of cable out to get the sonar fish this close to the seafloor. The sonar sends and collects backscatter sonar signals from the seafloor via this cable.

I did not realize how much work it takes to create the side-sonar images I have been looking at. These images beautifully depict the features of the ocean floor. You can see lava flows, fractures, and pillow mounds on a meter-scale. It is an amazing technique that enables you to feel like you know what is there. Yet, an incident at the beginning of the data collection intrigued me, and left me with a feeling of untouchable seafloor. We tried to identify features on an existing map with images we were collecting, but we could not see them. That gave us concern about the quality of the data we were collecting. We finally found that we were off from the position we thought we were at by more than 500m. The ocean floor is hidden beneath a deep-water column that does not easily show us the world we want to see. Of course, in reality, we are revealing it everyday with the help of incredible technology like ABE, Alvin, and DSL-120A.

We still have a lot more work to do in the three weeks remaining. I am very excited to see the rest of the data we collect and the results of this cruise. I am truly thankful for the opportunity to be on this cruise.

Aloha,
Tomoko Kurokawa

Pat Hickey, the Expedition Leader, on winch watch in the Computer Lab this morning. Ken Sims (behind Pat), a geochemist at WHOI, is monitoring the sonar data during his watch.

Margo Edwards, the Director of the HMRG group, and Paul Johnson, one of the HMRG data processing specialists, looking at the improved sonar data.

Patrick Hennesy, the Bosun, and Kevin Fisk, the Chief Engineer in the Main Lab.

Gavin Eppard works in the Alvin mechanical shop. He's been working the past few days on preparing the equipment to be used in the Alvin basket during our diving.

Maurice Tivey studying the newly produced DSL-120A sonar images of the east side of the East Pacific Rise.

A photograph of a piece of the new DSL-120A sonar data just collected from the east side of the East Pacific Rise axis near 9° 32'N. The record is of a several hundred meter diameter mound of pillows that probably erupted from a large fissure similar to the ones that extend north and south of the mound. Each half of the sonar swath is 500m wide. The sonar fish was being towed north on this line. White areas in the record are places where sound is strongly reflected back from the seafloor - like faults or mounds that are facing the sonar fish. Dark areas in the records are places where the acoustic return is lower or regions of acoustic shadow. The dark areas just east of the pillow mound are shadows from the various small peaks on this small hill, probably only 10-20 meters high, formed by volcanic eruption.

Phil Treadwell, the 3rd Engineer, and Alan Farrington, the Oiler, working on Alvin's lift-line winch high up on the A-frame. This is used to launch and recover Alvin.

Michelle Cooper plotting the position of the sonar fish on a bathymetric map today in the Computer Lab.

Pete Collins (right) flying the sonar fish by controlling the traction winch. The black lever he is holding allows him to pay-out or haul-in the fiber optic cable that connects the sonar fish with R/V Atlantis. Bob Waters is monitoring the navigation of the sonar fish.

John Cawley working on repairing ship's equipment today. The crew of Atlantis are constantly working to keep the ship in good repair so that we can do our work. The officers and marine crews working on oceanographic research vessels are the backbone of oceanographic research in the US - we couldn't do our research without them.

Al Bradley busy repairing ABE's 'brains'. We expect to be finished with our sonar survey by Friday morning. Then ABE get's its chance to show off.