7 November, 1995

November 7, 1995

Location: On Station 62 18' South Latitude x 57 14' West Longitude In an area of the Bransfield Strait where measurements of high crust temperatures were made in 1993.

Update: We spent the day on station which means that we tried to keep the boat in the same place for most of the day. This was a real challenge, because the winds were blowing at 40 knots for most of the day with gusts approaching 55 knots. It was a cold day to be outside. Temperatures of about 20 degrees Fahrenheit mixed with snow and sleet made it miserable to be on deck.

The coring crew was out on deck most of the day, testing a new sediment corer. Their plan was to take core samples of the sediments in this area to look for evidence of hydrothermal vents and to look specifically at the different layers of the sediment to get and indication of what sort of geological factors caused these sediments to be deposited by the sea in this area.

It took three trials to be successful with the corer. The first attempt was made from the stern (back) of the ship. They attached the corer, which kind of resembles a long stainless steel straw with weights on the top, to a large heavy cable and winch system at the stern of the boat. The whole corer setup weighs about 1200 pounds and is about 15 feet long. A problem arose because the weight of the cable, at a depth of 2000 meters where the samples were being made, was larger than the weight of the corer. As a result, they had difficulty detecting when the corer had reached bottom, and the first test was brought up with no sediment at all.

On the second attempt, they moved the corer to the starboard , (right) side of the boat and used a much lighter cable and winch setup to raise and lower the corer. The setup worked perfectly, and the scientists were able to determine when the corer penetrated the sediments. As they pulled the corer out of the water from its journey of 2000 meters in the ocean, the sediments shot out the end of the tube as soon as the corer hit the air. Some of the scientists laughed, some yelled as a result of their frustration with the devise. There wasn't much they could do until they got the corer back on deck.

Once on deck they were able to determine that a small pair of hinges at the bottom of the corer that are designed to open after the corer has been pulled out of the sediment had failed to close. This is what caused the sediments to fall out of the corer when it reached the surface.

The team made some minor modifications to the corer and sent it down for the third time. Just as on the second attempt, they were able to tell when the corer had pushed into the sediments. This time the hinges had closed and when they pulled the corer from the water, the core sample stayed intact in the corer. They brought the samples on board and into the wet lab, where the scientists spent nearly 6 hours taking samples and measurements of the various layers of the sediments. They also made observations of color, texture and grain sizes, as well as features of the sediment which were unusual or not typical for oceanic sediments. When the sampling process was done, the ten feet of sediment had been cataloged into small sample bags, and small plexiglass boxes so that future study of the samples could be made by them and other scientists back in the states.

The OSU team continued to look for signs of hydrothermal vents and took water samples using the CTD and made measurements for the presence of manganese using the ZAPS sled in the same area that the cores were taken. At this location they did not find any definitive evidence that vents were in this location, so the decision was made to move later in the evening to the site of a ocean volcano that had been identified by scientists mapping this area in 1993.

The plan for the night would be to take a number of water samples and ZAPS sled tests to see if there were any hydrothermal vents active in this location.

As we made the move to the location of the volcano, a much welcomed change in the weather followed us. The winds died down from 40 knots to about 15 knots. The air pressure began to rise and the seas became much gentler. A noticeable change in the stress level of the ship staff and scientists came with the calmer weather. The constant motion and jarring of the wind and waves takes its toll on you throughout the day. Since you are constantly moving and trying to maintain some since of balance, you attention is always being distracted. It is like trying to do two things at the same time. In rough seas, the seas take priority over science. With calmer weather comes a renewed emphasis on the work at hand.

As I ended my watch and prepared to go up to sleep, I looked through the starboard porthole in the computer lab. Due to the cold weather and snow, the porthole had frozen to form a tunnel of ice and icesicles which formed an eerie frame against the moving ice and sea. It had been a long and challenging day.


MB & JB: There has been a question about women on the ship. As far as the ships's crew goes, there is only one woman on the crew. She works in the ships mess. On the support staff, we have two women marine technicians and one computer technician. On the science teams, the University of Texas has two women and the Oregon State has four. Although most of the staff is men approximately 1/4 are women.

cketjpet: The first animals that I saw in Antarctica were birds. They are usually with the ship at all times. In calm winds the spend most of their time in the water. On the windy days they spend most of their time gliding in the breeze along side the ship. The second most common animals that I have seen are seals. They are pupping right now, but I have not seen any young as of yet. The last type of animals that I have seen are penguins. For the most part they are in their rookeries hatching young, and very few make it out onto the ice where we are. Hopefully in a few weeks we will see more.

The temperatures here range from 18 to 38 degrees F. There is not a whole lot of variation between daytime and nighttime temperatures. The wind is the major problem when you are out on deck. A calm day has winds of about 10 miles per hour. On the windy days the winds are 40 to 50 miles per hour.

In terms of seasickness, I was sick longer than I thought I would be. I personally was seasick for almost two days straight. Since my initial bout, I have been just fine, even though we have had some pretty severe seas. Others on the ship have gotten slightly nauseous every time we experience a major change in the motion of the ship. I expect that when we start our trip toward New Zealand that many of us will get sick again, because we will be bucking some strong headwinds and the boat will be pitching rather than the rolling that we experience mostly now.

MB on WASDILine: Greetings to all of the WASDI people. Thanks for your support and questions.

Jennifer J: The ZAPS sled is a package of instruments which sample the water for the presence of Iron, Manganese and Radon. The instruments are connected by a electrical cable to the ship so that the scientists are able to record data being collected on computers as the instruments sample the water for these elements. They are parcticularly interested in the presence of Manganese, because manganese is a key element that is found near hydrothermal vents.

The streamer is a 1200 meter bundle of wirers that are attached to special microphones called hydrophones. The streamer is towed behind the ship at a speed of 4 to 5 knots. There are large air guns which are pulled behind the ship in the water. These guns produce sound waves which bounce off the layers of the ocean crust at different speeds. The reflected sound waves are detected by the hydrophones on the streamer. Special computer programs interpret the data about the reflected sound received by the hydrophones and produce a picture of the layers of the earth's crust below the surface.

The Helium and radon which is sampled is dissolved in the water like carbon dioxide in soda. The gas stays in solution in the water because of the high pressure and cold temperatures at the depths the water is collected. The water is transferred to special copper tubes once the water samples are brought on board. These samples will be analyzed later at Oregon State. Some of the samples for radon are tested on the ship using special carbon filters which absorb the gas, and then instruments on the ship are used to determine the quantity of radon in the samples. There is not enough gas being released for bubbles to be visible at the surface.

The primary mission of this cruise is to collect data and make maps of the ocean floor looking for new evidence about volcanoes, plate tectonics and the geology of this area of Antarctica. There is much to be learned. Everything about this area of the world is still very new and exciting.

Return to Steve Stevenoski's Page

Contact the TEA in the field at .
If you cannot connect through your browser, copy the TEA's e-mail address in the "To:" line of your favorite e-mail package.