Mail Buoy
April 1, 2001
My name is Stacey Canchola and I am a student at Fullerton College studying Oceanography. Are you at liberty to decide how long you can stay at a given location in the Ocean, or do you have a rigid schedule that you must follow in order to stay on target with the expedition?
Hello Stacey:
When we go on an expedition, we know that it will last a certain length of time (in our case, 40 days) and that we leave and return to port on certain dates. That is fixed because there are other cruises with different groups of scientists on either side of ours, so the ship is very busy while it is in the Indian Ocean. However, during the cruise, there is a great deal of freedom as to how we spend our time. Of course, it is a little bit of a juggling act, as we always want to accomplish as much as possible! On this trip, we are hoping to visit two or three hydrothermal sites, but we have to make sure we do a good job sampling at each one. Hence, there are frequent discussions among the scientists on board about what the scientific priorities should be and the most efficient way to accomplish them.
Good question -- hope you will follow along and learn about some of the decisions we shall have to make as our cruise continues!
Susan Humphris
Dear Janet Costello,
We are writing to you from the Dana Hall school in Wellesley, MA and our class wants to know what skills and abilities you need to have (aside from school training) in order to be a successful medic at sea? What kinds of emergencies and/or illnesses have occurred on board Knorr?
Thank you very much!
Dear Students,
Thank you for your question. I am a registered nurse, with a special board certification in emergency nursing. I also have many years experience in intensive care, emergency room and ships nursing. In order to be a successful medic at sea, like anything you want to be successful in, you must work hard and pay attention.
Being a medic on the research ship is very challenging as you are the only one with medical training. We are often times in remote places in the ocean and it can take many days to get the patient to a hospital. You have to be prepared for just about anything. It may require that you go without sleep for a long time until you can get the patient to the hospital. Most of the time, people are pretty healthy here because you have to pass a physical to go to sea. But people do get sick and injured out here. I have had to take care of lacerations, broken bones, chemical burns, eye injuries, stomach problems, sea sickness, and even dental problems. You just always have to be prepared for anything at anytime to be a successful medic.
Thank you again for writing.
Janet Costello RN,CEN
Medical Officer RV Knorr
Dear Ms. Humphris,
We are a group of 8th graders from Dana Hall in Wellesley, MA and want to know if it is safe to witness an underwater volcanic eruption? Have you ever or do you expect to witness one on this expedition? Are there any signs that an eruption is about to happen on oceanic crust like there are on continental crust? What are the environmental implications of this expedition?
Thank you,
Dana Hall Earth Science.
Hello there 8th graders at Dana Hall:
As far as I am aware, no-one has ever witnessed a volcanic eruption along the mid-ocean ridge first hand. Some scientists came close in the early 1990’s when they were doing a survey and discovered a lava flow on the East Pacific Rise that had buried a lot of hydrothermal vents. They think that the eruption occurred only a few weeks before they were there.
One of the problems is that we do not have very good ways to detect underwater eruptions in most of the world’s oceans. However, in some places, such as off the coast of Washington and Oregon where the mid-ocean ridge is close to the continent, scientists at the National Oceanic and Atmospheric Administration “listen” for earthquakes using special instruments called hydrophones that are moored in the ocean. Several times over the past few years, earthquakes have been detected along this part of the ridge system, and expeditions have been mounted to go and study the volcanic and hydrothermal activity that might be related to the earthquakes.
In terms of signs that an eruption is about to happen, it is likely that there are signs similar to those seen on continents when volcanoes erupt. Such signs probably include more earthquakes than are typical and inflation (or swelling) of the ground in the area. Marine geologists and geophysicists are just beginning to place instruments on the seafloor to measure these things continuously so that we can see how underwater volcanoes behave.
You asked about the environmental implications of our expedition. We try not to disturb the hydrothermal vents and their biological communities too much when we observe and sample them. We take only the samples that we need to identify the organisms and determine what the hydrothermal system looks like.
Hope you will continue to follow along!
Susan Humphris
This question is going to be directed to Bob Collier and Marvin Lilley: The Hydrothermal Vent Prospecting Team.
I was just wondering what other kind of instruments do you use to find the hydrothermal vents. And also I was wondering how they produce the sulfide.
Thank you.
Stacy Misiak
We look for the temperature signal from hydrothermal fluids but this is often tricky due to the extreme dilution of the fluids and the complex temperature structure of the ocean. We have to look for temperature differences of less than 0.02 degrees but our CTD is capable of accurately measuring temperatures to better than 0.001 degrees!
Hydrothermal fluids are acidic and contain very high concentrations of many dissolved gases and metals when compared to seawater. When these fluids mix with cold seawater, some of the metals precipitate to form particles. Most deep sea water is very clear, with very few particles, so finding the “murky” water from the vent fluids is one of the most common and sensitive vent prospecting tools. Hydrogen sulfide, which produces a rotten egg smell in the lab, is generated under the seafloor when seawater reacts with the new ridge basalt at very high temperatures (some of the sulfur comes from the original seawater, some comes from the rock).
These temperature and optical signals can be recorded by CTDs or MAPRS (see the web site Hot Topics). Although the full CTD with water samplers requires its own wire and occupies the full attention of the ship, the MAPRS can be attached to almost any wire we lower from the ship. Temperature and optical sensors can also be left on the seafloor attached to moorings or at permanent “observatories” awaiting a nearby volcanic eruption. You can find out more about observatories at the NSF RIDGE program website (http://ridge.oce.orst.edu/) and NOAA’s NEMO website (see http://www.pmel.noaa.gov/vents/home.html).
If the particle or temperature signals suggest that a vent is nearby, we collect water samples and analyze them for dissolved hydrogen, methane, iron, and manganese. These results almost always confirm or refute our suspicions.
One other common way that we know where to look for vents is to look for the unique vent organisms (that can almost always find vents first!) They are quite easy to spot in bottom photographs ... and they are 100% accurate!
Finally, we “listen” for them ... NOAA has been perfecting the use of underwater microphones (hydrophones) to listen for earthquakes and seafloor eruptions. (See the Hot Topics archive on the AHA program). When a certain type of sound is recorded, we can be pretty sure that an eruption is taking place with LOTS of hot fluids!
IN FACT, just such an event is occurring RIGHT NOW on the Gorda Ridge off southern Oregon (sadly, several of us out here in the Indian Ocean will miss it). You can watch information about the event, as it evolves, at the NOAA website: http://www.pmel.noaa.gov/vents/acoustics/seismicity/nepac
/gordaridge01.html
OK - back to work processing CTD data.
Cheers from the Plume Team
Hello Dive and Discover Explorers:
My name is Merrit Tompkins and I am a student teacher with Jill White at Harding Elementary School in Corvallis, Oregon. We have been following your voyage and the 27 students in our third grade class have a few questions for you:
1) How fast does the Jason ascend and come up?
2) How deep has the Jason ever been?
3) What do the creatures near the vents look like? Do they have eyes?
4) How long did it take to repair the Jason after it broke?
5) How heavy is the boat with all the equipment on it?
6) How did you get there?
Also, could you please tell Mr. Collier hello from all of us. His daughter is in our class and it is great to have the opportunity to teach the children about science with a real experiment to follow involving local community members.
Thank you so much for this opportunity and we all look forward to hearing from you.
Sincerely,
Mrs. White’s Third Grade Class
Hello Mrs. White’s Third Grade Class:
What good questions -- thanks for sending them in! I will answer them one at a time:
1) How fast does the Jason ascend and come up? Jason is usually lowered and retrieved on its fiber optic cable at 25 meters per minute. The ocean is about 2500 meters in the area that we are working. Can you calculate how long it takes Jason to get to the seafloor?
2) How deep has the Jason ever been? Jason can go to 6000 meters (almost 20,000 feet), but I believe that the deepest it has been is 5000 meters.
3) What do the creatures near the vents look like? Do they have eyes? Good question! You would recognize some of the creatures at vents, like crabs, mussels, and shrimp. However, there are others that look very different -- like the tubeworm. Check out the Vent Biology infomodule in the Deeper Discovery part of the web site to learn about the animals. Some of the animals do not have eyes (it is dark down there) but use other ways to find their food and the place they live.
4) How long did it take to repair the Jason after it broke? When the thruster broke on Jason, the Deep Submergence Operations Group worked very hard to fix it. Jason was back in the water within a day.
5) How heavy is the boat with all the equipment on it? Whew -- that was a tough one! I had to ask the Chief Mate, Kent Sheasley, to help me! He calculated that the ship and the equipment weigh 2, 944 long tons (there are 2,240 lbs in a long ton). If you multiply that out, you will find out that the total weight is 6,594,560 lbs! That’s a big number! But here is how you can picture it. A full-grown elephant weighs 6 tons, so the weight of the ship and the equipment is about the same as 550 elephants.
6) How did you get there? I assume you mean how did the scientists get to the ship? Originally, we all planned to fly from where we live to the Seychelles to meet the ship, our equipment and the crew. However, our equipment got stuck in Mauritius, so some people decided to meet the ship there instead. I joined the ship in the Seychelles and sailed with it to Mauritius.
Hope this answers your questions -- Mr. Collier says hello!
Susan Humphris
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