Although Lucille and the AUV team were not involved in Leg 2 of NOAA's Deep Water Coral Cruise, the team continues AUV operations on the NOAA Vessel MacArthur II off the California coast near the Channel Islands for the final leg.
Lucille completed her dive successfully and after a quick look at the photos, it looks like this is a rocky area. We will pass this information on to geologists and they can use it to update their maps.
We just finished reviewing the data to find out why Lucille ended her mission early. Her thrusters were working but it seems that she may have gotten tangled around a rock as she turned. We are running out of time on this night watch so we have decided to do a mission in shallow water to finish the night. The mission will take place at the top of the bank in about 300-325 meters of water. Based on geological maps, this area appears to be rocky, but it won't be clear until we see the bottom with Lucille's cameras.
Lucille went down to a depth of 499 meters and was clicking along on her mission but ran into some trouble right after her first turn and we had to abort her mission. Through the telemetry messages Lucille uses to keep us informed, we can see her rising to the surface. We are headed out to the deck to pick her up.
Tonight we are going to try an east to west transect in deeper water at the northern edge of the bank. The AUV went into the water at 10PM and we are hoping that all goes well.
We were able to run Lucille along the bank for a while but we got into some very shear rocks that Lucille could not navigate around. We had to make do with only about 700 images of the bottom. What we saw, however, was beautiful. There were many sponges and corals as well as many bank rockfish (Sebastes rufus). We even saw bank rockfish in sponges as you can see in the picture below.
All of the Leg 3 scientists, including the AUV team, came aboard McArthur II this morning. Leaving from Santa Barbara, California, we steamed 3 hours to our study site "Piggy Bank." A bank is a raised part of the ocean floor, like an underwater hill. Piggy Bank was named by local researchers. I think they chose it because it was amusing, but I am told that if you look at some of the geologists' maps and squint, it really does look like a pig. We are getting Lucille ready to go in the water tonight. Our first dive will be on the top of the bank at about 300 meters depth. We will zigzag across the bank from east to west taking pictures and measurements.
Lucille and the AUV team will be off the Washington Coast on the NOAA vessel McArthur II looking for cold water corals and the fishes that live among them. The AUV team will be blogging about the operations of Lucille.
Operations have been suspended because of weather and we are headed to port. Leg one of the West Coast Deep-Sea Coral Research Cruise is now complete. The AUV team will return for Leg 3 in Southern California. Let’s cross our fingers for better weather for Leg 2 scientists. As sailors say, we are wishing them, “fair winds and following seas.”
The seas are still pretty rough. We have one more night of operations before we head to port. We have decided to wait for less risky conditions before sending Lucille out on another dive.
The weather has picked up considerably from this afternoon. We avoid putting the AUV in the water if the weather might get worse and make it difficult to pick up the AUV from the water when it is done with its dive. We have decided to wait and make sure the weather is not going to get worse.
We took a quick the first look at some of the images from the dive. There were very interesting views of fish and habitat but no corals. We are hoping the weather holds and that we can do another dive tomorrow.
Lucille performed very well and we managed to complete a six hour mission that included taking photographs and gathering multibeam acoustic information. Mutibeam acoustics uses sonar to produce a high resolution map of the seabed. Our hope is to integrate photos with information from the multibeam acoustics to create one picture that shows both details of the seafloor and the animals that live there.
The weather has improved so we are putting AUV Lucille in the water for another dive.
The winds are still increasing. We always consider the weather to make sure operations are safe for both people and Lucille. We are worried that if the weather worsens that it could be difficult to recover Lucille safely with the ship rocking around. We will spend the evening downloading data and hoping that tomorrow’s weather is better. I have included one of the pictures that we have downloaded. We have only looked at a few pictures so far but this picture shows some of the typical habitat on this dive, large boulders. Tucked in around them you can see the backs of rockfish.
Dive #1 is complete and Lucille performed well. The winds increased to about 30 knots while she was underwater so the recovery could have been challenging. Thanks to the very capable bridge officers and crew it was not. The ship guided us right next to her, we hooked her up to the winch and on board she came with all of her pictures – over 7000. We tied her safely to the deck since we are rocking around a bit and then began to download the 62 gigabytes of data. Time for some breakfast and then off to get some sleep.
After one small hitch, she went into the water at 11:30 PM and she is off and running. We will get messages from her every minute or so. That allows us to track her progress. She will send us information about such things as her depth, location, remaining battery power, and how many pictures she has taken. One of us will carefully monitor those messages on the computer for the next five hours for any signs of trouble. We can always signal her to come to the surface if there is trouble. This can be a little monotonous but on the first mission of the cruise you are always a little nervous. Let’s hope nervous energy keeps us all awake until 4 AM. It has been a long day.
We arrived at the study site in the early AM. Lucille went into the water first thing so we could ballast her. Her buoyancy depends on the weight of sensors and the salinity of the water so we carefully check at the start of a series of missions so her weight is perfect. You SCUBA divers will be familiar with this process. Lucille floats at the surface and we slowly add and subtract weights until she is just slightly positively buoyant. This ballasting is very important since one of the fail-safes on the Lucille is a dead weight. That weight is attached to the AUV with a link that corrodes at a known rate in seawater. While Lucille is underwater if she should lose power or for some other reason not be able to motor to the surface, the link that holds the dead weight will corrode over time and break, releasing the drop weight, allowing Lucille to float to the surface.
After ballasting, we ran a few tests to make sure she was following her programmed instructions. That went very well, she turns when her programming says turn and she dives right on cue. Ballasting and the other testing also gives us an opportunity to practice putting Lucille in the water and picking her up. Work on board a research vessel has to be carefully choreographed. Between the bridge officers piloting the vessel, the crew who operate the winches, handle lines and keep us all safe, and the scientists releasing or retrieving the AUV, everyone must know their role. As with any dance, you perform best if you practice a bit first. We spent some time practicing recoveries and deployments while we were doing the ballasting and other tests. Now everyone knows their role: what lines they handle, what safety gear to have and where they need to stand. We have finished all of our preparations and Lucille is ready to be deployed. The weather is good with some wind and we plan to put her in the water at 10 PM. The area we have chosen is one about which little is known. Lucille will be in exploring mode. We will program her to run a long line of zigzags. After we review the images we can go back and do some more detailed work if we find corals or other interesting features.