Mail Buoy

January 27 responses:

How old is the hydrothermal vent? Would it ever close?

Hydrothermal vents have very different life spans, depending on where they are. Some could be active for only a few years, while others might last for decades. “P_vent,” a vent we’ve studied in this area, has been active since 1995, while “Q_vent,” another one nearby, appears to be extinct. The East Pacific Rise, the area of the sea floor below us, is very volcanically active, so eruptions happen all the time. As they do, they change the “plumbing” of the sub-surface, stopping the flow of some vents while creating others. On this trip, for instance, we think we’ve found a relatively new vent that may have recently formed. We’ve called it “Teddy Bear” due to the fuzzy sheets of bacteria that cling to the rocks there.
           
Best,
Dionysis Foustoukos

What is the most useful sensor or sensors you use on the ship and on Jason?
           
Amanda Meyer
Memorial High School, Eau Claire, Wis.

Dear Amanda,

There are lots of sensors aboard the ship and aboard Jason, but being able to say which ones are most useful will vary depending on which scientist you ask. It depends entirely on each researchers’ objectives. Nadine Le Bris, for example, is using many different sensors on the sea floor that can measure pH and temperature, as well as hydrogen sulfide and other chemicals. She’s using those to map the chemistry of a vent site over time. For my work, temperature sensors are probably the most important. We’re taking samples of vent fluid both to analyze its chemistry, and to provide fluid to other researchers here on the ship that are using it to grow microbes in the lab. To get a good sample, we need to know when we’re in the absolute center of a vent’s outflow (which is usually the hottest part of the fluid plume.) That way, we’ll be certain that we’re pulling in only pure vent fluid, and not seawater.

I should mention that there’s one more sensor we use in the lab—our noses! The human nose is far more sensitive than any sensor we can build at the moment, so we can often tell if chemicals called sulfides are present in a sample by taking a quick sniff. You can’t miss them—they smell just like rotten eggs.

Best,
Jeff Seewald

When Alvin explored hydrothermal vents in 1977, the instrument that measures the temperature melted because of the heat of a black smoker. What material is on Jason's temperature instrument that protects it from the heat?

Sam 
The Common School
Amherst, Mass.    

Dear Sam,

The temperature of vent fluid isn’t high enough to melt most metals (except maybe lead). If you try to use a sensor that isn’t specially built for extreme temperatures, however, you’ll definitely break it if you put it into fluid coming from a hydrothermal vent. Vent fluid is also very corrosive, and can eat through stainless steel. Because of this, the temperature probe on Jason is made out of titanium, a metal that resists corrosion and can withstand high pressure and temperature.

Best,
Jeff Seewald

Is Jason working well?
           
Luisa and Andrea
LK, Grade 12, Gymnasium Ramstein-Miesenbach, Germany

Dear Luisa and Andrea,

Thanks for your question. Yes, Jason is working incredibly well. We spent 397 hours (about 16.5 days) at the East Pacific Rise, and had Jason was in the water for 324 of those. For two days, we had to keepthe vehicle on the deck due to rough weather, but other than that, it has never worked better.

All the best,
Tito Collasius

Dear Lena, Lena, Silke, and Annika,

The Mariana Trench and the vent sites we’re studying at the East Pacific Rise have one thing in common: Both were formed due to movements of the Earth’s crust. As one tectonic plate (a huge section of the crust) slides underneath another, it folds some of the rock downward in the process, forming a trench. Sometimes, there are black smokers associated with that movement—not at a trench itself, but somewhat farther away. As the plate that is “subducting,” or sliding under the surface, starts to re-melt deep beneath the surface, magma (molten rock) can bubble up and create active volcanoes. If those volcanoes form underwater, black smokers may form with them. Vents like these can also form where plates spread apart, like they do at the East Pacific Rise. In that case, we call the volcanic area a “mid-ocean ridge.”

Best,
Jeff Seewald

Dear Selina, Lisa, Steffi, Marcel, Nico, Jan, and Jana,

Hydrothermal vents have been around for about four billion years, or as long as the Earth has had a solid crust and liquid water (oceans). In fact, some of the earliest forms of life on the planet may have evolved at hydrothermal vents!

Best,
Jeff Seewald

Did anyone of you ever dive with a submarine (Alvin) and how does it feel to spend a long time in it?
           
Katharina S., Ann-Cathrin, Aline, and Katharina F.
LK, Grade 12, Gymnasium Ramstein-Miesenbach, Germany

Dear Katharina, Ann-Cathrin, Aline, and Katharina,

Because of what you’re seeing outside, you often forget you’re sitting in a tiny little sphere. You only realize it when you’re on your way down, but once you’re down there, you get very comfortable. You don’t feel any movement, really, so it’s just like sitting in a small room. On the way down, things can get pretty busy, though. Pilots and crew need to check different electrical systems to make sure everything is going smoothly. Also, as unnerving as this sounds, one of the things everyone has to do during the first 300 meters of the dive is look for leaks. I was on a dive that had to be aborted once because of a small leak in a seal. That’s very rare, however, and the leaks are never big—just a drop or two. Of course, if you see one, you immediately turn around and come back. The way Alvin is designed, the entire sphere compresses under pressure, so in general, you get tighter seals the deeper you go.

Best,
Sean Sylva

Hi, All –

Diving in Alvin is very exciting, because you’re actually on the sea floor. Once you arrive, it’s very dark, and when the pilot turns the lights on in front of the submarine, you can suddenly see the bottom. It does get a little uncomfortable towards the end of the dive, because you’re sitting in an awkward position for about eight hours, and your body gets a little stiff. It’s also cold at the bottom, but you’re usually doing so much that you don’t really notice it too much. Plus, you have lunch with you—there’s coffee and sandwiches, and there’s usually music playing. It’s very civilized. Alvin actually has a great stereo system!

Jeff Seewald

How do organisms in the Hadopelagial orientate themselves?
           
Katharina S., Ann-Cathrin, Aline, and Katharina F.:
LK, Grade 12, Gymnasium Ramstein-Miesenbach, Germany

Since there’s no light in the deep ocean, organisms living near the vents can’t see, so they use other senses to move around and orient themselves. Vent crabs, for instance, are blind, but can hear noise and vibrations just like their relatives in shallow water. Many organisms at vent sites also have chemosensory abilities (a sense of “smell”) that helps them tell where they are.

Best,
Horst Felbeck

Dear expedition team,

How small is a Micro Organism? Why are they so important on the expedition. How many different kinds of Micro organisms are there? And if the expedition finds more Micro Organisms, do you think they will be new species? And how many new species do you think you'll find on the see floor?

Thanks you very much for your time and commitment to science and exploring new places that humans have never visited. 

Wade Nygren
7th Grade, Palos Verdes Intermediate School
Palos Verdes Estates, Calif.

How many new species have you discovered so far on the mission?

Eli
Diamond Middle School
Lexington, Mass.

During this expedition, how many new organisms did you discover using Jason by the hydrothermal vents and what species did they evolve from?

Thank You
Chris
Verdes Intermediate School, Palos Verdes Estates, Calif.

Hi Wade, Eli, and Chris,

Thank you very much for your interesting questions!

Microorganisms are in the range of few micrometers (a micrometer is 1/1000 of a millimeter). I would say that the average for deep-sea microbes is 1 to 3 micrometers.

There are hundreds of thousands, maybe even millions, of species of microbes on the planet. As for the total number of microorganisms on Earth, this is one of the big questions in environmental microbiology. We are not sure, but one estimate is that there are around 5 x 1030 microorganisms on Earth, which is quite an impressive number.

At deep-sea hydrothermal vents, microorganisms form the base of the food chain, and they are fundamental to the ecosystem. They are food for many large animals.

I am not sure how many new species we will find during this expedition, but I hope we will get many. We won’t know if we have new species until we get into the lab and test their DNA. This will keep us busy for a while and help us to better understand hydrothermal vent ecosystems. Keep your fingers crossed for us!

I also want to thank you for cheering us on during this expedition. The excitement of exploring new places is one of the reasons I became a marine biologist.

Thanks again,
Donato Giovannelli