Christopher Moon Blog Legs 2 & 3

Jason is recovered after a long 10 hour dive in the dark of night. M. Elend, University of Washington; V23

5 September 2023

Dives resumed! The weather let up and Jason was able to go back down this time at Axial base. There is a sense of urgency on board as engineers and scientists alike rush to get everything done in time for our transit home on late Tuesday. At this point the days and hours are starting to blend together as I my hours of sleep decrease but I’ll try to summarize the last two days.

The first dive of the Leg started at the Axial Base (2600 m), sending down a new HPIES insrument and cables, a process that takes a remarkable amount of attention to detail due to the cable management and geological obstructions. These dives are grueling taking up to 10 hours.

After my shift ended at 0800, I took a quick nap too wake up in time for lunch, a classic hot dog. From there a quick science meeting and informative talk from Han who showed us their senior thesis. From there it was back to logging, the second dive of the day had started, on the way down we were treated to a large jelly fish the biggest yet covering both of Jason’s manipulators, as well as a swordfish on the previous watch.

The stars from the deck of the Thompson. C. Moon, University of Washington; V23.

With new equipment going down, it means old equipment comes up, meaning they need to be cleaned. Alex, Alessia, and I got to work cleaning and coiling cables as well as scrubbing down one of the old camera mounts that not long before sat 1500 m down in the International District Hydrothermal Field. A fun yet disgusting task as the silty mud from the ocean floor tends to have a smell that just sticks to your clothing leaving you no choice but to make a full change.

As night fell upon the boat, a couple of us students made our way to the lounge and had a Minions movie night. However, half way through, Han interrupted us and exclaimed, “there are stars and bioluminescence of the bow”. None of us had to be told twice and we rushed to the deck, it was the first night we had seen stars due to the clouds and as we looked into the water being churned by the propellers of the ship, green flashes lit the water up.

The R/V Rachel Carson retrieving the AUV. Credit: M. Elend, University of Washington, UW.
The Jason crane lowers the ROV for the first dive of the day. Credit: M. Elend, University of Washington, V23.

27 August 2023

Yesterday, the crew completed all of the dives planned for the  ASHES site. However, there was an exciting twist as we were called to the rescue of an AUV belonging to MBARI stuck at 40 meters water depth. Jason was sent to dive and attach a floatation device to bring the AUV to the surface, allowing our sistership the R/V Rachel Carson to pick the vehicle up for maintenance.  

As the day concluded, we once again entered into transit, b-lining for Southern Hydrate Ridge. For me, this meant a much-needed rest, or so I thought. In the morning the first dive of the day started at 0630. If it weren’t for my essential cup noodle, I doubt I would’ve made it to breakfast. On an empty stomach, minutes can feel like hours in the rocky ROV van control room as I learned the first day.

There was something a bit more special about this dive. As we began to descend into the depths, a shark flashed across the screen for only a millisecond, but it woke us up in the van. As I studied the screen more carefully a dozen tiny fish appeared, but instead of quickly disappearing they appeared to follow the descent of the ROV, remaining on the screen for a dozen seconds before finally being outpaced by the winch’s speed. This continued, even to the darker depths that we entered, where the bioluminescent organisms were the only other lights besides the high beams on board Jason.

At that point, my shift had ended, so instead of sticking around to watch the remainder of the dive, I headed to the galley in hopes of catching the last of the delicious breakfast prepared every morning. I could go into more detail, but beginning to describe the food would lead me to no end, as not only is the food amazing but the selection endless.

The crew hoists the CTD back onto the deck of the Thompson. Credit: M. Elend, University of Washington, V23.

25 August 2023

The first 36 hours onboard were fairly calm. Learning the ins and out of the ship was exciting, but dampened by my focus on keeping my seasickness in check as the ship transited to our first destination at the Axial Base ~ 22 hrs offshore.

Last night was the first time I got to not only see the operations of the crew, but my first chance to participate in the ops myself. By the time my first shift came around this morning at 4 am, I had gotten my sea legs under me. Coincidentally, 4 am was when all the action began, upon our arrival at the Axial Aase as the ship came to a halt above the site.

Our first task was to open the Niskin water sampling bottles (Niskins) on the CTD, carefully attaching the cords to their associated hooks, which would eventually fire their tops and bottoms, trapping ocean water inside at thedesired depths.

Oceanography undergraduate Alex Rose teaches me how to process samples. M. Elend, University of Washington, V23

After prepping the CTD with School of Oceanography undergrad Alex Rose, we were brought to the computer lab where the CTD would be controlled and the data  collected. From there, RCA research scientist Mariela White would inform the person on the winch what depth she desired for each water collection. The Niskins started at 220 meters and ascended in increments of 20 meters filling two bottles at each stop over the span of about an hour.

The CTD was carefully hoisted back over the hull of the ship and back into the hanger, where Alex, Andrew Paley (and RCA lab technician) and Mariela began collecting samples into carefully labeled bottles.

At this point the other students and I were able to help log and collect nutrient samples into the database both on paper and online. As we were working on collecting samples Brian and I, the two students on watch, were pulled aside to help with operations in the “van”, the control center for everything ROV Jason related.

The ROV Jason being lowered into the NE Pacific ocean. M. Elend, University of Washington, V23.

At 0600 the descent of Jason began; it’s cameras documenting its’ slow and steady progress through the shallow soupy-looking ocean water. Looking carefully, the strands and dots that at first appeared to be random debris started to move, sometimes darting or sometimes making slow progress across each of the cameras around ROV. They took many different shapes but most commonly looked like, pencils, tiny jellyfish, shrimp and our favorite “the disco ball” a dodecahedron shaped creature with luminescence on each point.

This particular dive, the mission was to retrieve a malfunctioning profiler pod stuck on its journey towards the surface. The ROV Jason descended to only 140 meters before hovering to cut the cable stopping this instrument from shooting to the surface. In one swift stroke the engineers in the van cut the cable and the platform disappeared from view careening towards the surface. At that point my shift was over and I was replaced at the recording chair.

Stepping out into the light from the dark van was similar to stepping outside a movie theater after a long movie. The light from the newly risen sun blinded me while my eyes adjusted. Looking out into the vast sea a small orange instrument protruded on the surface bobbing up where Jason had done its work.