Recently Asked Questions

Chinook Middle School

We were on the research vessel the Atlantis when we discovered the field, and Lost City is located on the Atlantis massif (or mountain). The mysteries its holds brought back the intrigue of the mythological city called the Lost City of Atlantis.


No, the pressure inside the sphere remains nearly the same as pressure at the surface, so Alvin can come up at ~75 feet per minute.


Our challenge is to learn how they formed, whether they have been active for thousands of years, and how their unique chemistry supports life. If we can understand the processes involved, we may gain insights into what vent systems were like when the Earth was very young. Such knowledge may help us search for vents and life on other planets.


The discovery of the Lost City was one of those rare times when you are in the right place at the right time. We did not go out to the Atlantis Massif to find the field, it was complete luck and shows that there is still much that we do not know about our oceans.


The towers are light in color because they are made predominantly out of calcium carbonate (CaCO3). These minerals do not contain a lot of metals or other elements that give color to other types of rocks (for example, elemental sulfur is bright yellow). The microbes are very, very small--hundreds and hundreds could sit on the head of a pin. So, they appear light in color. In some hot spring environments, some types of microbes form yellow colonial mats--which reflects the fact that they use sulfur in their metabolisms.


A great question, which we do not yet fully know the answer to yet. We know that the chimneys are made out of the same minerals that make up the rock (or stone) called limestone. Limestone is composed of minerals made out of calcium carbonate (e.g. calcite). Some organisms can actually help calcite to crystallize. But, we do not yet know if this is happening at the Lost City Field.


Life at a small scale is incredibly abundant at Lost City. Small, single celled organisms coat actively venting parts of the chimneys and life within small openings in the rocks. Larger animals such as mussels, sea anemones, and sea urchins live near or on the structures. There are also very large corals and fish that live there.


The Lost City Field is not the shallowest vent field. It is at a water depth of 700 m or ~ 2100 feet. There are many high temperature fields on numerous large submarine volcanoes that ring the margins of the continents, and there are shallow warm to hot springs off of volcanoes like Iceland. In the shallow systems, many of the fluids are actually boiling and this process helps enrich metals such as gold and mercury. It is not likely that sea level would be lowered enough to expose the Lost City Field, but if it was exposed the chimneys would probably be broken off or eroded away by waves breaking over them.


Alvin weighs about 35,000 lbs. While it seems too heavy to float, there are large blocks of a special, dense foam called "syntactic foam" that makes Alvin buoyant in the water. When Alvin is deployed, it carries an extra 960 lbs of weight to make it sink to the seafloor. Air tanks balance that weight until the pilot is ready to take it to the bottom, then the air tanks are flooded with seawater. When the sub reaches the bottom, half of the weight is released so that it can move freely. When ready to end the dive, the pilot releases the rest of the weight and Alvin comes back to the surface.


There are fish at Lost City -- BIG FISH called groupers. These fish are bluish-grey in color and seem to be attracted by Alvin. In 2000 we saw one of them on the discovery dive to the field, and yesterday a pair joined us for part of the dive. These fish are 3-4 feet across and often come very near the windows of the submersible. They may be attracted to the warmth of the lights, but we don't know this for sure. There are some other smaller types of fish, but we only saw a few during the dive. However, we saw lots of small shrimps and swarming, gnat-like critters called anthropods.


Debbie Kelley answers: I became a scientist because I wanted to understand how our planet works-an innate curiosity in part. In addition, a major thrill and excitement comes from finding out an answer to a puzzle you have been working on for several months, or even maybe years. When all the pieces fit together, for me there is a great satisfaction. Finally, there is always the hope that we will discover a new ecosystem like the Lost City.


We believe that these valleys or escarpments form by a couple processes. The south face of the mountain is bounded by the Atlantis Fracture Zone, which has numerous small earthquakes every year. In addition, alteration of the rocks along the southern face causes them to expand by as much as 40%. This expansion may cause the rocks that form the very steep hillsides to fracture and become unstable. This process, coupled with shaking by the earthquakes may result in landslides, which progressively eat away at the mountain.


The vent fluids from Lost City are certainly expelling gases (e.g. methane, hydrogen) and some chemical species (e.g. calcium, some trace metals) into the ocean water. However, this is a natural process that may have been going on for several thousand years. You might think of the plumes emitted from the vents as similar to plumes that form during volcanic eruptions or warm fluids emitted from hot spring systems similar to Yellowstone. All off these systems contribute chemicals, gases, and energy to their surrounding systems, but they are a natural process that has kept our environment in balance for millions of years. Thinking of it in this way, it is difficult to say that the chimneys are polluting the ocean. Methane and hydrogen are critical to the survival of microorganisms that live in the vents, so they do not see these gases as a pollutant.


The background water is warmer than the deeper ocean water here, but it is not particularly warm (less than 50F). Even on the top of the mountain, which is at a water depth of about 2100 feet, we have not observed many fish. A few groupers routinely follow us around when we are in Alvin, and we have seen a few smaller fish, but not much else. Nutrients for larger animals are not in high abundance. The only "human" presence in the area is us, although every 2-3 days a cargo ship passes in the distance.


We do not call the chimneys at Lost City white smokers (even though they are white!). The white smoker name is reserved for chimneys made out of iron, sulfur, lead, and zinc sulfide minerals that have high temperature (250-300C) plumes of white "smoke" coming out of them. Much of the white smoke is caused by crystallization of very fine-grained minerals made out of anhydrite, a mineral composed of calcium and sulphate (SO4). In some of these systems, the sulfide minerals are deposited beneath the seafloor, depleting the fluids in metals. Mixing of these depleted fluids with seawater causes anhydrite to form. In contrast, the fluids at Lost City are clear when they come out of the carbonate towers and they are much lower in temperature (40-70C). They are also very poor in metals and they do not contain anhydrite. For this reason, we do not call them white smokers.


The Alvin ballast weights are made out of steel that degrades and oxidizes on the seafloor. At Lost City we enter the area from outside the vent field, and drop weights for ballast before we enter the work area. On the way out, the pilots drive away from the field before dropping the final weights. The terrain is very steep in this area and we only have to go 100-200 m away before the slopes drop several hundred meters.

In this way, we do our best to not degrade the environment. However, what we think of as “toxic” to humans is not toxic to many of the organisms that live around venting systems. For example, in black smoker environments there are bacteria that utilize arsenic, mercury, and cobalt during metabolic activity. Many also thrive on hydrogen sulfide.


Debbie Kelley answers: I was on a cruise with the Canadian remotely operated vehicle called ROPOS in the Northeast Pacific Ocean in 1996. A huge storm came up very suddenly, and unexpectedly that resulted in 80 mph winds and >20 foot waves developing in a matter of hours. This happened while the vehicle was 7000 feet below the surface of the ocean. By the time we pulled the vehicle up, nearly the full force of the storm was on us and, unfortunately, the fiber optic cable broke that connected the vehicle to the ship. At nearly the same time, the engines on the ship quit for a while, and we were not able to maintain visual contact with the vehicle. We searched continually for three days with the help of search planes, but we never found ROPOS. Luckily, there is now a new ROPOS.


W. Bruce Strickrott answers: Well, the answer depends upon what submarine you're talking about. Alvin can go to 4500 meters, a little more than 14,500 feet. Normally we'll operate in the neighborhood of 2500 to 3000 meters but if need be we can go to the 4500 meter maximum. Other deep ocean research submarines, like the French Nautile and Japanese Shinkai, can go deeper, 6000 and 6500 meters respectively. In the past the deep submersible Trieste made the only manned trip to the deepest part of the ocean, the Marianas trench in the Pacific near Guam. Currently our institute, Woods Hole Oceanographic Institution, is looking into building a newer, deeper diving replacement for the current Alvin. Perhaps in a few years you'll be able to watch the new Alvin's operations via the Web.


The French will likely be out here within the next year with their submersible, Nautille. We do not know when we will be able to return because we or others must submit proposals to the National Science Foundation to get money to return. This usually takes about a year or more after a proposal is submitted because it is critically reviewed by other scientists, a panel of experts at NSF, and finally the program managers at NSF. There are only two times a year (August and February) when we can submit proposals. After this, the next stepping stone is finding time on a ship when the submersible or remotely operated vehicle is available. This can mean a 1-2 year wait sometimes because of previous grants that have ship time already scheduled. It is a complicated process, but we are used to it and it just means that we have to plan ahead.


The minimum age of the mantle rocks can be estimated based on paleomagnetic data. The magnetic minerals in the rocks align their magnetic signatures to the orientation of the magnetic field at the time that they were near the seafloor. But, sometimes this field reverses its orientation. By dating fossils and rocks that were formed during these periods, the age of the reversals have been calculated. At sea, we use an instrument called a magnetometer, which "maps out" the strength and orientation of the minerals within the shallow oceanic crust. At Lost City, this method indicates that the mantle rocks are 1-2 million years old. This is a minimum age, however, because the rocks do not obtain their final magnetic signatures until they are near the surface.


Sometimes when we work 18-24 hour days, or more, we do get pretty tired. Certainly 16 hour days are not unusual for a lot of us. But, we do this because we only get a very limited time (in this case 22 days on site) to do all of our work and so we must make the best of it and get the most we can done. What commonly keeps us awake is a passion about what we are doing and the people we work with. When everybody is working together and you have lots of people who are also working hard with you, it is not difficult to stay awake...it becomes a routine that many of us thrive on. When we need to sleep, we do and surprisingly that is a difficult thing to learn. Many people on their first cruises are so excited that they do not want to sleep because they are afraid they will miss the action, and that is something we have to watch out for. You just learn to pace yourself. When you do crawl into your bunk, there is nothing like the gentle movement of a rolling ship or the sound of water going past the hull to put you to sleep.


Pat Hickey, Alvin Expedition Leader, answers: The pilots and technicians who operate and maintain ALVIN are a diverse lot..Some are degree'd engineers while some, like myself, have an enormous amount of experience working in offshore applications such as the Navy and oil field. When we hire new people, we typically look for someone who has formal training, university or college, in mechanics, electronics or electrical systems. A base knowledge of computer systems is also a plus.

But all the education in the world can not prepare someone for the extended time we all spend at sea. Typically, we spend 4 months assigned to the ship and then take a 2 month vacation. Not bad, hey, 4 months off every year? But you have to remember that you spend your time at sea with on average, 55 other people, share a room and a bathroom, eat with the same people day after day, and when at sea, can only walk for 275ft in any one direction. Things can get "cozy" at times. This is the primary reason that new people don't stay past their first 4 months at sea.

On the plus side, the food we eat is excellent, we are in port on average every 3 weeks and so can get off the ship for a few days and, during the times when we are on vacation, can live anywhere in the world we like when not on the ship.


While there are no chemical engineers on this cruise, there are chemists and there are engineers working on the science! Oceanography in general, is a very multidisciplinary science and people usually come into oceanography after first getting training in some more specific field. There's no reason why a person trained in chemical engineering couldn't work on a program like this- it would just be a matter of developing a specific project that makes use of their training. I often think of a chemical engineer as one who takes known chemical reactions and scales them up to industrial sized processes. That's not something we do out here. However, there is a lot of interest in biochemical processes and enzymatic chemistry that takes place at hydrothermal vents and these are the kinds of science that I would expect a (bio)chemical engineer might make use of. As you study your chemical engineering, you should try and take some oceanography courses and visit some oceanographic institutions- you might very likely find someone who knows of a project that could use someone with your training.


Dave Butterfield replies: Well, the Atlantis could never be mistaken for a cruise ship, but there are some diversions out here to keep people entertained in whatever free time they have available. Usually, that free time is pretty limited. Meal time is very important, especially dinner when everybody shows up and the conversation flows. The Atlantis has a great galley staff (Larry and Linda) and they keep us well fed. One of the biggest attractions for recreation is the ping pong table, which is set up in the main lab right next to my work area. (I often get hit in the back by ping pong balls while extracting water samples from the day’s dive.) People really enjoy the fun and competition, and a moving ship can add an extra dimension to the game. A tournament is in progress, and everybody is wondering who can beat the captain. Many people find that exercise is essential to keep from going crazy being in the same space every day. There are some weights, a treadmill, a rowing machine, a stepper, a stationary bike, and a punching bag in various places on board. There is a large collection of movies on board (The Sopranos seems to be popular on this trip). Some people like to play cards or other games. There are a lot of interesting people to talk to, so it’s not hard to stay entertained.


We look for signs of what kind of meta-bolism the microbes are utilizing. (Do they eat methane? excrete methane? how about sulfur or hydrogen?) We use three basic strategies to do that: culturing, epifluorescence microscopy, and molecular techniques such as DNA sequencing. For example, we might find that adding methane to culture tubes promotes growth and that the DNA sequences of these microbes are similar to other microbes with methane metabolisms. We might even find one of the genes that are necessary for growing on methane. Since many different types of metabolism are likely operating at the Lost City, though, our actual results will probably be much more complex and confusing, for awhile at least.


This is a topic that we really do not discuss much but it is always in the back of our minds. Scientist really do not know much about the details of earthquakes out here in the deep oceans, but we do know that there are a lot of relatively small ones. We see evidence of rock slides on all of the steep slopes we dive on and these are probably triggered by earthquakes. It is also possible that the tall, slender spires of the Lost City could topple during an earthquake. So there is always the chance that rocks and other material could come sliding down the cliffs while we are on the seafloor. I am not aware of anyone ever seeing a rock slide from Alvin, but it definitely could happen. There really is nothing that can be done to avoid these types of events. I should say here that safety is the top priority of the Alvin pilots and so they are very cautious about getting close to anything that could be dangerous on the seafloor.


On this expedition there are 24 scientists. The number 24 comes about because this is the number of beds that are onboard the Atlantis that are reserved for scientists. The scientific party on this cruise includes professors that do research and teach at universities, students that attend the universities, and technical staff that help the professors do their work. Because there is so much to learn about Lost City and so many different kinds of studies to be done, we wanted to take as many people as possible on this cruise. It is great to be able to learn different things from all the people out here who study the animals, rocks and fluids.


Bruce Strickrott replies: You might think that in the cold ocean depths that Alvin would have problems. The truth is that our submarine operates better when the water temperature gets colder. Average dive water temperatures are around 1 to 4°C. Most of Alvin's oils and equipment are designed to handle these low temperatures with no noticeable affect on performance. Only the sub's batteries, essentially a controlled chemical reaction, are affected by the colder temperatures. Ironically, it's the warm water that poses the greatest potential for disaster. Water around many deep sea hydrothermal vents can reach temperatures in the neighborhood of 300°C. We've even found water with temperatures as high as 380°C in the Juan de Fuca Ridge area off the coast of western North America. Alvin's viewports are made of a special acrylic material, and as the outside water temperature rises the viewport's ability to withstand the local water pressure diminishes. Luckily the hot water is very localized and it's easy to steer clear. As pilots, we have strict operational guidelines that govern our depth when the water temperature rises.


Adelie Delacour answers: Thank you for this question, Audrey!

I was a little bit afraid at the beginning of this cruise, because my English is not very good and I thought that would be difficult to understand what the people will say. And that was right!! But after almost four weeks, I can say that is a very good experience for me and I’ll never forget it. I learned a lot of things about the Lost City vent field of course, my main interest on this cruise, and also about the American culture. For example, I tried the traditional peanut butter and jelly sandwich and I like it. But I think that if you eat it, you can go without eating again for a long time… Another positive point of this cruise is that my English is a little bit better. And I would like to thank my friends on the cruise for their help.


Most of the samples that we bring on board are frozen whole. Frozen tissues are easier to extract DNA from at a later time than preserved tissues. Samples that are not frozen are preserved in either formalin or ethanol. Preservation in ethanol also allows for later extraction of DNA (though it doesn't work as well as with frozen tissues), but often any coloration that the animal has will be leached away by the ethanol. Sometimes it is important to have an animal keep its coloration in order to identify it more easily. Formalin preservation keeps the animals looking pretty much like they do in life. Often we will preserve the first specimen of a species that we collect in formalin as a voucher sample. Depending upon how the tissues are to be used later, different preservation techniques are used, but for us, formalin, ethanol or freezing works best.


The fluids at Lost City are lower in temperature (less than 100°C) and have different compositions and gas contents than fluids at black smoker vents. There is more hydrogen and methane in the Lost City fluids and very little CO2 and H2S. In addition, the rocks underneath the Lost City system are altered mantle rocks, called serpentinites. The reactions of seawater with the mantle rocks produce high pH fluids with high calcium and near-zero magnesium. When these fluids mix with seawater, which has high magnesium and contributes carbonate ions, calcium carbonate and magnesium hydroxide are deposited. The white carbonate material is what makes up the spectacular structures at Lost City. In a black smoker system, the fluids have a low pH and are rich in metals, CO2 and H2S; they deposit sulfide minerals on the seafloor. The black smoker vents also typically discharge at temperatures above 300°C.


There are a couple different ways that the ship stays in one place. The first is that the bridge (the place where all the controls are to drive the ship) is manned 24 hours a day--there are always two people on the bridge at any one time. It is the tallest part of the ship and has many windows so that people have a very wide angle view of the ocean around them. This is so they can see passing ships, things that might be floating in the water (like logs) that could damage the boat, and commonly, they are the first to spot whales or dolphins that come to visit us.

The crew "manning the bridge" can manually drive the boat in any direction they choose. Sort of like driving a car. When Alvin is in the water, the ship stays in roughly the same spot, but they do not hold it very tight on station...meaning that it can drift 100's of feet and that is ok. If it starts drifting too far, the crew can give extra power to engines that drive large propellers in the hull of the ship and this allows them to drive the boat in any direction at the speed they choose. However, sometimes we need the ship to stay in an exact spot and not drift more than a few feet. In this case, the driving of the ship is taken over by computers. The crew types in the exact location that we need the ship to hold station at, and then the computers take over telling the propellers what to do, how fast to turn, and in what direction. They do this by a very sophisticated system.

The ship has a system that can communicate with satellites that fly overhead. By communicating with multiple satellites at one time, the position of the ship can be determined very accurately. This satellite system is called GPS for short, or the Global Positioning System. The computers onboard continually communicate with the satellites and update the position of the ship constantly. This information is processed by the computers and the computers adjust the engines and propellers to keep the ship in one place. This method of driving the ship is called Dynamic Positioning.


Vent microbes are not considered plants (plants need sunlight and there is very little sunlight below 1000 feet), but at deep-sea hydrothermal vents, they serve a very similar function as plants. Vent microbes use chemicals like hydrogen sulfide or methane instead of sunlight for their energy. The microbes form the base of the food chain (really more like a web) for larger animals. Some animals are referred to as hosts, like tube worms, mussels, and clams, because they have microbes (called symbionts) that live inside their trunks or their gills.

These symbiotic microbes change chemicals in the vent fluids into energy, but unlike plants that produce energy (or carbon) from sunlight, these symbionts produce carbon from the chemicals in the fluids and then give that energy to their host. A very important question for vent biologists now is trying to understand how energy flows through a food chain at vents. Some key questions include: Which microbes use which chemicals for their energy, how much carbon energy do they produce, and how much of this do they give to the larger animals?