One of the most frequent questions I get when talking to people about the field sites I study is - "Where is that located?". I figured this may be a question to some of you had as well. So while I am stuck in quarantine, I figure I would use this time to discuss:
Where is the Southern East Pacific Rise located?
To get started, I need to back up a few steps to help explain the processes that make the East Pacific Rise. The East Pacific Rise is what is knows as a Mid-Oceanic Ridge spreading center. Mid-Oceanic Ridge spreading centers are found globally where two tectonically active plates spread apart from each other. In the Pacific Ocean, "the ring of fire" - a ~40,000 km (~25,000 miles) tectonically active region around the rim of the Pacific - is know to be an area of increase volcanism and earthquakes. As a part of the "ring of fire", the East Pacific Rise extends from the Gulf of California to Antarctica, and is made of multiple plates that are sliding or spreading apart from each other at variouse rates. The Southern East Pacific Rise just referrers to any part of the East Pacific Rise that is located from the equator to Antarctica. On this expedition, we will be specifically exploring and sampling sites between 15-18 S along the Southern East Pacific Rise.
What makes these a good site for hunting for hydrothermal vents?
Along the East Pacific Rise, the rate at which the plates spread apart from each other varies. The Southern East Pacific Rise is what is known as the an ultra fast spreading ridge. This means the plate spread apart at a rate of 141-162 mm/yr (5.6-6.4 in/yr). To put this in perspective, the rate of parts of the Northern East Pacific Rise (e.g. a fast spreading ridge) is ~110 mm/yr (4.3 in/yr) and the Mid Atlantic Ridge in the Atlantic Ocean (e.g. a slow spreading ridge) moves at 20-50 mm/yr (0.79-1.97 in/yr). These different rates impact the volcanisms and shape of the ridge along the ocean floor. Due to the fast rate of spreading along the Southern East Pacific Rise, the ridge is constantly being flattened and reformed creating a relatively shallow ridge formation comparted to other Mid-Oceanic Ridges.
But more importantly, Mid-Oceanic Ridges (and specifically the Southern East Pacific Rise) make excellent sites for hunting for underwater volcanoes (i.e. hydrothermal vents). Hydrothermal vents are formed when seawater is circulated through hot, chemically reactive, porous crust, creating hydrothermal fluids. The hydrothermal fluids are less dense (reaching temperatures between 350-400 C or 662-752 F) then deep ocean water (2 C or 35.6 F), creating underwater hot-springs that produce chemically-rich plumes. The vent chimneys are created through the precipitation process of sulfide or other minerals building up, focusing the stream of hydrothermal fluids into the deep ocean.
In addition to these high temperature vents, there are low temperature vents that are classified by being less particle-rich and having fluids between 50-100 C (122-212 F). Recent work along the Southern Pacific Rise, has shown that the parts of the ridge we will be visiting are dominated by diffuse low-temperature hydrothermal vents. This makes an exciting place to study and investigate hydrothermal processes and the role of low-temperature diffuse flow in these systems.
Why do we care?
There are many reasons to care about hydrothermal systems. For one, they are exciting places to explore, but also hot beds for biological diversity in the deep sea, mineral production, and questions about origin of life. In some cases, certain species are only found along specific ridge systems-an area of active study.
In 2013 a ~4300 km (~2700 miles) hydrothermal plume was found emanating from the Southern East Pacific Rise. To this day, it is still the largest known hydrothermal plume. What was more surprising was how far certain trace elements (iron, manganese, aluminum, etc) plumes extended as well. Iron is depleted in much of the ocean, and initially thought to precipitate and settle out of hydrothermal plumes. However, over the last decade, we have discover multiple mechanisms for iron to be stabilized and transported away from the vent and into the ocean interior. One of these mechanisms is with metal binding-organic ligands. Metal-binding organic ligands stabilize, and aid in the utilization of iron for marine microorganisms. Our motivation is to investigate and characterized iron-binding organic ligands in hydrothermal plumes along the Southern East Pacific Rise. We are specifically targeting low-temperature systems, but also hope to be able to compare it to a few local high-temperature sites as well. Understanding how iron is stabilized and protected from oxidation, as well as utilized by microorganism within/around the hydrothermal plume is critical for constraining the global and local geochemical impact of hydrothermal ridge systems, like the Southern East Pacific Rise.
The last three days on the ship were a roller-coaster. In the early morning hours of July 31, both Sentry and Alvin were declared out of commission and were in the process of being repaired. This sent the schedule into flux and rethinking how we could use the tools (CTD Niskn Rosette, Multicorer, etc.) still on board to collect our priority samples. On board with some of the other hurtles we were overcoming, this news was both physically and mentally taxing. It also didn't help that most of us were sleep deprived from troubleshooting problems in the days prior.
However, with all that in mind, we came together as a group and made it through. I personally, learned how to deploy and recover a CTD Niskin Rosette with my fellow Team Water members. We became really good an communicating what we needed from one another. We got in such a nice grove we became like a NASCAR pit crew! On once occasion we deployed, recovered, and redeploy all in the span of 15-20 minutes. Those last two steps taking place with in 5 minutes of each other. Since there are straps and ropes that need be used to secure or safely launch the CTD Niskin Rosette over the side of the ship, this is a really fast turn around. I wouldn't recommend this under normal circumstances, but it was only done to fix a kink in the wire that holds the CTD Niskin Rosette. With that said, we were pretty impressed with our four man team! Especially since this was a first time most of had deployed/recovered this equipment. Overall, the reworking of the schedule brought leg one shipboard science party together. We got really good at being an extra pair of hands for those who needed it and figuring out the planning/executing for the following couple of days. We came together as a team, and it was nice to know people had your back when you needed it.
On the evening of July 31, we finally got some good news with the repairs on HOV Alvin were successful. The pilots and crew were expecting we were going to be ready for the two dives planned on August 1. All was good and I was finally able to start getting excited about diving in HOV Alvin.
However, after the first dive was launched on August 1, the wind picked up. If the wind is above 25 knots it becomes to dangerous to be deployed HOV Alvin. For the next few hours it was touch and go as to whether myself and my dive partner were going to be able to dive later that afternoon. Finally around 1pm the wind settled down enough to be able to recover and get HOV Alvin ready for a second deployment around 3:30pm. It was finally time to get ready for an experience of a lifetime!
I have skydived, bungee jumped, and SCUBA dived, but going down in Alvin was one of the coolest experiences of my life! Being locked into that hatch with two other people, and exploring the ocean floor was incredible! Additionally, this experience has allowed me to starting thinking about how I can use the tools and capabilities of Alvin to explore other seafloor habitats (i.e. hydrothermal vents) to answer scientific questions There is still a lot to learn, but as was said at the beginning of this experience we are the "new face of deep-submergence research." Big responsibility, but also very exciting to see what we are going to find!
So today has been a long day with many, many meetings. I'm starting to get little exhausted. My home lab would classify this as the "beamtime sillies". However, since I am not currently at the Advance Light Source, it would probably be more appropriately named "ship-time sillies". In either case, brain function is decreasing and exhaustion is taking over. Therefore, I am going to keep this short and leave you with some pretty pictures to look at!
Today has been long but very productive. There has been lots of renegotiating with how water is going to be collected on this cruise to meet everyone's priority needs. Why is water so important? Well, for us specifically in Team Water (and a few other teams on board), water is not just water. In each drop of water we have bacteria, plankton, chemicals, etc. information. This becomes really important when you are trying to understand a system in its entirety. In other words, it tells us a lot about the ecosystem(s) we are study on this research cruise. This is very important when we want to model and understand all the components that go into or are utilized by that ecosystem. In the big picture this information could then be used to refine global models of sources and sinks on the seafloor.
However, the problem is we aren't all able to sample from that one small drop of water. Additionally, there are certain instruments require a baseline detection level to get viable data. This requires us to filter large volumes just to measure the concentration of one chemical signature, or extract DNA from a certain depth. In other words, water can be high value out here!
The good news is we (the Team Water members on board) have been utilized the telepresence set up to scheudle meetings with our team ashore. This means we are able to revise plans in real time which is invaluable! I hope they feel the same because it have been great having their input out here.
In other news today, I did a live braodcast from the ship with mentor/science educator Dieuwertje Kast at USC. I got to interact with her and 25 high school student that are apart of the USC Neighborhood Academic Initiative (NAI). There were some technically difficulties, but we tried to work through them. Facebook messenger was a live saver for this! Given this is the first time R/V Atlantis has ever attempted something like this/this is training cruise for all science and telepresence parties aboard, I would call that a success.
Overall, today has been a day for troubleshooting, and testing! Enjoy the photos below!
Well I think Im going to turn in for the night before I over-exhaust myself. After all, we are only on day 2.
PS. Photos are finally up for day 1! Have a look!
Today has been a whirl-wind! First day out at sea, and I am starting to get a feel for how things work. I'm trying to sit back and absorb information in the hopes of being able to step up when asked or needed. However, currently it has been a fire house of information. The most important thing I've learned is communication is key while out here. Being in contact with our shore-based team at URI Inner Space Center, the different crew member and teams on board, and the individually within our scientific teams means there is lots of room for miscommunication. Having point people for each objective hopefully cuts down on telephone being planned, and something being misinterpreted. There are lots decisions being made based different teams sampling needs, safety, or capabilities of the instruments that we are using. Even though priorities have been planned, flexibility is needed when unexpected situations arise (i.e fog this morning in port during departure). I'm having to consistently remind myself to pace myself. I know from working at the Advance Light Source in Berkeley, CA that you don't want to expend all your energy on the first day. I need to make sure I can keep the stamina up for at least the next 4 days while I'm on the ship. And if I am being honest, probably also when my cohort switches to the URI Inner Space Center. This is going to be exhausting, but in a good way!
Today we have been mostly streaming out to our site. We finally got on site about ~3 hours ago and started our first AUV Sentry dive. It was streamed live on YouTube. If you are interested in any of the live video streams from the ship you can visit them here at this link.
I personally have been a part of a small team that has been getting things ready for the first HOV Alvin science dive on Saturday. My specific role is to be in charge the Niskin bottles that will be deployed on Alvin's sled. With some last minute changes to the size of bottles available, I took the lead on connecting to our scientists at URI Inner Space Center to work out a new/modified plan of action. Sort of crazy to be talking with our fellow scientists in the middle of the sea! Once that was completed, 4 of us worked on creating a first draft of how we were going to map everything on the was going to go on Alvin's sled. We then consulted with the the Alvin team, to revise and finalize the plan. Tomorrow morning (bright and early), the final touches will be made on configuring the basket just in time for Alvin to launch at 8am. Since Alvin is scheduled for an engineering dive tomorrow, this will be a test run on getting the sled set up for Saturday. Eek! Fingers crossed everything goes smoothly with no surprises!
It has been a busy first day! Time to turn in before I crash. Hope to add some pictures tomorrow to this post. Here is to a smooth night with AUV Sentry!
PS. The FB Live event mentioned yesterday, has been rescheduled for 2pm EST July 29 (tomorrow) using YouTube Live (click here). I will be giving a tour of the ship and answering questions of high school students who are apart of the USC Neighborhood Academic Initiative with mentor/science educator Dieuwertje Kast. Feel free to tune it!
The bags have been unpacked, rooms have been moved into, and anaerobic chambers plumbed (see picture). These last two days we have inundated with great information about the cruise, shipboard etiquette (always keep the the coffee pot full!), and how to become social media experts to relay our science. How am I doing?
So what am I going to be doing on this cruise?
My role will be filled as a member of #TeamWater. Woot woot! There are many goals within our team, but to summarize, we will be collecting water from the water column, methane seeps, and bottom water. In addition, our group will be targeting collection of crabs, mussels, and other microorganism communities that are present. We are hoping this will allow use to understand the chemistry and biology of these different environments. Personally, I am hoping to collected end-member fluids from the two methane seeps we will be visiting. I am planning to look at carbon and sulfur minerals/particles within those fluids. Why I am doing this? Well since this is a training cruise, I am hoping to learn how to sample end-member fluids on HOV Alvin and apply this knowledge to hydrothermal vent, aka underwater volcanoes. This is the main environment I have been studying for my dissertation. If interested you can learn more about the project here. Additionally, I am going to be learning how to sample for these fluids once shipboard, and do some minor sample processing in a glove bag (see picture above). We use a glove bag to store our samples without oxygen. The hope is to avoid having our minerals oxidize like a rusty nail or an apple left on the counter Therefore, we gain a more accurate picture of the in-situ environment. This is important when modeling a systems influence locally, regionally, or globally.
In the larger view of this cruise, we will be collecting many other types of samples. Some examples include mapping the ocean floor with AUV Sentry, collecting sediment and rocks to understand their microbial communities, and understanding the biology and chemistry along the ocean floor (octopus, coral, etc.). Lots of awesome science to learn about our ocean and seafloor!
We will also be broadcasting our day to day activities. If you want to tune in and see it live, click here. Once on the URI Inner Space Center's site, click on the live feed for R/V Atlantis. Maybe you will see me walking around or working on the deck! I will be in the ship until August 2, and the will be on shore at the URI Inner Space center to August 9.
An additional opportunity to see me on the ship will be on July 29. I will attempting a live Facebook video from the ship ~1pm EDT for a science educator/friend back in CA. Tune in if you are interested!
As a final note, I figured out how to add my Twitter feed on the right side of this blog. It is the live feed of what I am currently working on the cruise as well as my research. Hope you enjoy!
Colleen L. Hoffman is a scientist by day and adventurer by night. She is currently a postdoctoral scholar at the University of Washington.
All photos are the property of Colleen L. Hoffman, unless otherwise noted.
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