Brendan and Giora analyze gases in hydrothermal fluids from the chimneys called 'Diva' and 'Escargo' in the International District Hydrothermal Field on Axial Volcano. The fluids are sampled using highly specialized tiranium water samplers to collect 'gas tight' samples, and analyzed onboard the Thompson using a gas chromatograph. Photo Credit: Deborah Kelley, University of Washington.
16 August 2103
This is what it looks like out here. A line between the sea and the clouds, following the horizon in all directions. A few days have been sunny, but most have been almost just like this. Almost. Each day is slightly different. The wind may pick up, the swell might increase, the sun may break through. To be content out here, I pay attention to the daily differences, however small they may be. Jelly fish float past, a shark fin cuts through the water. A mola flipper flaps as its side is pecked clean by floating albatross. A beam of green light appears as the sun sets; ripples form in stratospheric clouds.
“The sea contains many surprises for him who has his floor on a level with the surface and drifts along slowly and noiselessly. A sportsman who breaks his way through the woods may come back and say that no wild life is to be seen. Another may sit down on a stump and wait, and often rustlings and cracklings will begin and curious eyes peer out. So it is on the sea, too. We usually plow across it with roaring engines and piston strokes, with the water foaming round our bow. Then we come back and say that there is nothing to see far out on the ocean.”
- Thor Heyerdahl, “Kon Tiki”
While the Thompson cruises at twelve knots with “roaring engines and piston strokes,” it can be incredibly calm when the ROV is deployed and we remain stationary above a target. It’s no wonder that the creatures of the sea come by to investigate. If all personification were to be removed, the creatures of the sea are doing what they have always done; we just happen to be floating nearby with warm tea and freshly baked scones. A far cry from Heyerdahl’s balsawood raft expedition across the Pacific.
It’s difficult to capture what its like to be out here, let alone what its truly like to do anything. How can you recreate a moment or a scene? Does that picture of the sunset truly do it justice? Did you really see the sun set, did you actually watch the rainbow fade? I sit down, wait and watch, and “often rustlings and cracklings will begin and curious eyes peer out.” Too bad that most of the time those eyes belong to America’s Favorite Rubber Chicken.
11 August 2103
This entry is a reflection on the cruise as it stands now, with roughly one week left until we head back to Seattle. After 39 days at sea, I’m looking forward to walking on land for more than a few hours at a time! I’ve spent my time working hard, gaining confidence in collecting data and gaining experience at sea. I finally saw the stars last night; the weather took its sweet time to clear.
After leaving Newport, we spent a day at Hydrate Ridge, where I’m collecting data for my senior thesis (see previous blog post). We strapped water sample collection bottles to the side of the remotely operated vehicle and spent the end of a dive driving around the methane seep field that was imaged a few weeks ago. We found two methane bubble plumes, and were able to collect a water sample 1-2 meters away from the source of the bubbles. While the vehicle was being recovered to the surface, we drifted down-current to collect more water samples. In the absence of a sonar survey and with a heavy package under the ROV, this was the best that could be done. These samples will be analyzed back in Seattle for dissolved methane concentrations.
I’ve presented my work twice while onboard, which has been good practice for when I present my final results. It was beneficial to have students, educators, scientists and engineers listening, because of the probing questions (not all of which I had an answer to) and the great feedback on ways to improve my presentation. Being onboard for this long has been an incredible learning experience, for several times I was able to decide what to do with the ship when the weather was too bad for launching the ROV. During one night of poor weather, I planned and ran a sonar survey over Northern Hydrate Ridge, which is not a focus of the RSN project, but it is also venting methane into the ocean. I also gained experience in planning a dive and directing portions of it, which required clear communication and extensive patience. I was relieved when we finally found the bubble plume source that had been picked up with the sonar system, and was excited to see the environment that these plumes were coming from.
I was recently sent my very own rubber chicken, who has been unofficially named “Mr. Chicken.” It turns out that this chicken is extremely photogenic, and he’s been making an appearance in the live stream whenever possible. Keep an eye out for the next sighting… Also, be sure to secure the wand-tip of a pressure washer before testing it by pointing it over the side of the ship. Those things sure do sink quickly.
31 July 2013
I’ve been out at sea now for 29 days, and have been relying on my scheduled laundry day to tell me that it’s Saturday. It’s been an exciting and busy 29 days, full of late-night CTD casts and multibeam sonar surveys, broken up by tedious ROV dives and meal times. Time has gone by rapidly, and I’m always surprised that it’s time to eat again (I always feel like I’ve just finished my previous meal).
On the last few days of Leg 1 (during which we visited Axial Seamount briefly), we dove on Southern Hydrate Ridge (SHR), where methane gas is seeping from the seafloor and making its way up towards the sea surface in bubble form! I decided in June that I would focus on SHR for my senior thesis and would look into exactly how much methane is reaching surface waters above these seeps. Another way to put it: the vertical methane concentration gradient between the seafloor and surface waters. It’s an important thing to study because there is a significant volume of methane hydrates trapped beneath the seafloor along continental margins, and methane gas has 23 times the radiative capacity of carbon dioxide. These under-water/under seafloor storage sites for a highly radiative gas in solid form could be a major source of atmospheric methane if the hydrate were to dissociate and methane gas were to reach surface waters. It has been hypothesized from preserved seafloor-dwelling organisms that, during the Late Paleocene Thermal Maximum 55.6 million years ago, there was a large release of methane gas that may have further increased planetary warming.
During Leg 2, poor weather near the coast prevented us from spending a lot of time at Hydrate Ridge, so we ran out to Axial to lay some cables and get ahead of schedule. There were two good sunsets during those two weeks; as the sun set over the horizon (or, more accurately, as the Earth rotated away from the sun on its own axis), I could see faint colors playing off each other just before the sun disappeared. Despite spending less time at Hydrate, I was still able to collect a plethora of data: three CTD casts to collect water samples, three multibeam sonar surveys to determine the location and height of plumes, and two ROV dives where a plume was imaged from the source to 200 meters off the bottom as water samples were collected. Most of this occurred over the last 24 hours of the leg, so sleep came quickly as we headed towards shore.
Leg 3 has been equally as busy, as I have taken on some additional responsibilities while continuing to work on my thesis. Since we’ve been laying down cables, the cable-lay route sometimes needs to be altered, either to avoid a hazardous area (a large collapse zone) or to change the start or end points. Mitch Elend, who is onshore for this leg, has developed a method for doing this, and I’ve been completing these as needed (at any time of the day or night). I’ve also been documenting the ROV dives: collecting any data produced and photographing anything that goes down or comes up. This includes a piece of a hydrothermal vent that weighted more than 100lbs! My artistic side has also emerged, though only to make markers to place on the sea floor.
There’s four days left until we get into Newport, where we’ll spend two days unloading empty cable reels and loading on more instruments and people. I’ve heard that we will also be getting a fresh shipment of food…