Juan de Fuca Ridge Cruise
July 20 - August 1, 2000
Over 650 km (~400 miles) off the Washington-Oregon Coast
July 23: Day #4
Log Entry: Today was a great day! We had 2 more successes with the coring sled, saw some beautiful seafloor geology along with some deep-sea creatures who decided to check out our vehicle, got some beautiful glass samples from the rock corer in the wee hours of the morning, and were visited by a swarm of "By-the-wind-sailors", and some other larger jellies.
Tiburon dove for about 10 hours once again, and it was overall a very successful dive, despite a few problems that we encountered along the way. We obtained two rock cores using the rock coring sled, and everything was functioning flawlessly. The solution to the interface problem we were having earlier has been solved. We did, however, run into another problem during this dive. When the manipulator arm, the robotic "claw" was moved to the far right, where the sample buckets are located, the "wrist" would start spinning around out of control. It was apparently a wire that was getting pinched when the arm was in one certain position. This prevented us from reaching 3 of our 6 wax corers, but we were still able to get a good number of samples. We were all very excited when the cores arrived on deck, since we were again coring into basalt, the hardest type of rock to obtain a core from. We were rewarded with 2 beautiful core samples. This type of drilling had never been performed before on Tiburon, especially at such depths (2000 - 3000vmeters). The coring sled was removed after today’s dive, and won’t be used again until its next cruise in late August
During the dive we saw some beautiful deep-sea animals, including a deep-sea ray and some unusual looking sea stars. The albatross are still with us, hanging out behind the boat. The seas were so unusually flat and calm today that the vast ocean surrounding us on all sides looked more like a lake!
A current brought some jellies by that we probably would not have seen in rougher water. The by-the-wind-sailor is a jelly that floats at the surface and uses a sail-like structure that protrudes into the air just like the sail on a sailboat. As we looked out along the water surface, we could see at least 15 or 20 little sails poking out of the water. Greg Moretti caught one with a bucket and brought it up on deck in order to get a close-up picture. They are beautiful animals!
After labeling, photographing, and storing all of our samples, we spent the night getting wax samples off the A-frame on the stern again.