2/9/2014 – Pure Dredgery

Katy writes:

Kelsey and Gene rocking out

Kelsey and Gene rocking out

We started for the Totten Glacier area, our main study area, at around 11:45am GMT on Wednesday, February 7th. Our shift on Thursday the 8th began with processing the dredges, starting with our most recent dredge that targeted the Eocene-Oligocene boundary for the second time (importance of that temporal boundary is discussed below). First, we cleaned each rock individually from small pebble to boulder size. We arranged them on a table in the dry lab into the three rock categories (igneous, sedimentary, and metamorphic) and then roughly subcategorized those groups. Once the rocks were dried and laid out on the table, Gene helped us finalize our sorting, and discussed what we found. The sedimentary rocks are the most important because they can tell us about past depositional environments. After we finalized our categories, we counted, photographed, and packaged the samples (1,029 total!). This took us about 9 hours to complete, leaving four dredges left to process (with each dredge having 7 to 394 total samples, which all went a lot quicker!)

Sunrise on the back deck

Sunrise on the back deck

That same day, we had a science talk regarding our dredging and seismic results, along with overall Cenozoic climate change trends. Amelia discussed the trend of overall cooling that we have seen over the Cenozoic. This was determined using oxygen-18 isotope records, establishing an ice volume record throughout the Cenozoic. In 2000, magnesium-calcium paleothermometry was used to isolate sea water temperatures from the ice volume record, showing a 12°C overall cooling since the Mesozoic. From these curves, clear climate transitions were shown at the Eocene/Oligocene boundary (~34 million years ago), the Middle Miocene (~14 Ma), and the Pliocene/Pleistocene boundary (~5 Ma). It is still being debated what is causing this cooling, but two current hypotheses are 1) ocean heat transport due to the opening and closing of oceanic gateways and 2) overall decreasing atmospheric CO2 due to changes in seafloor spreading, uplift, and weathering. Continue reading

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2/10/2014 – Entering Totten

Michelle writes:

1-P1010313We are just about 6 nautical miles from the edge of the Totten ice band and should be able to break through the sea ice into some ice-free water adjacent to the coast by this evening. Our watch shifts now demand a higher level of attention because we are in un-chartered waters; there is no pre-existing data from this area. Every seafloor feature that shows up on the screen on the Knudsen bathymetric profiler has never been seen before. NBP14-02 will be the first cruise to survey the seafloor and collect geological and physical measurements of the sediment and ocean currents.

Now, all planning is in overdrive. At the transition between shifts, there is usually a PI meeting at the navigation table or in the Chief Scientist’s room. These meetings include deciding which sites to hit first, which group will run their instruments and in what order. As we steam toward Totten Glacier, the researchers running the seismic instruments are planning their lines (the distance between two waypoints on which they will make their measurements).

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These images are very important because they will be high-resolution images of the ocean bottom and the sub-bottom down to about 400 m. That is tens of millions of years of a sediment record in one picture. The seismic images show the various layers and points of contact between geologic periods. For example, we may be able to see the boundary between the Eocene and Oligocene. Continue reading

2/3/2014 – Mertz Glacier Science Plan

Tasha writes:

Today marks the beginning of our sixth day underway and the crossing into the beginning of an entirely new world. We crossed 60 degrees south and have committed to continuing our travel directly south to the Mertz glacier; we expect to make it to the edge of the continental shelf on the morning of the 4th. To prepare us for our arrival in East Antarctica and for the beginning of a flurry of science that will be taking place, we listened to a couple of brief science talks about past science and our current objectives at the Mertz glacier.

And after that, we didn't let the penguins drive the boat any more...

And after that, we didn’t let the penguins drive the boat any more…

One of our objectives will be to acquire geophysical (seismic) survey data that will satisfy the requirements for future deep sediment drilling in the area. Seismic surveys will be conducted using two air guns that transmit sound pulses to the sea floor. This energy is powerful enough to penetrate 1 or 2 kilometers down into the sediment and underlying bedrock basement. When the sound waves encounter density changes in the stratigraphic layers (e.g. transitions from clay to bedrock), some of the energy reflects back up to the surface of the ocean where we have a seismic streamer (array of hydrophone receivers) that will detect the sound and record it.

Vessel telemetry, 3.5 kHz sub-bottom profiler, multibeam sonar, and other assorted toys

Vessel telemetry, 3.5 kHz sub-bottom profiler, multibeam sonar, and other assorted toys

We then translate the recorded sound to an image that will be used to create a map of the sediment layers below the seafloor. The map is based solely on the time it took for the sound to travel from the guns into the sediment and back to the receivers. These maps of the sub-bottom have many applications. Continue reading

10/30/2013 – Slow and Steady

Tasha writes:

I was excited to see what kind of machinery the Gould had working for us behind the scenes, so at dinner last night I asked the Chief Engineer, Mike, if he would be willing to give us a tour of engineering. He agreed and today many of the scientists went down after breakfast to check out the engine rooms. I used to be in the Navy and love learning about all things that make a ship work so please excuse my nerdiness in the following explanation of the engineering systems.

[Vessel specifications and some schematic drawings can be found via our Links page.]

Not winning any races

Not winning any races

In Control Central, where the watch-standing engineer monitors and controls the entire engineering plant, Mike walked us through the general components of his systems. There are two main diesel Caterpillar engines on-board with 2,300 horsepower each and a max combined speed of 10.2 knots for the Gould – not the speediest vessel out here. Her typical cruising speed is right around 10 knots, and in heavy currents that could result in speeds of 18 knots over ground running with the currents or 3 knots against (things could take a while). Continue reading

10/30/2013 – Gravity, Nausea, and Cape Shirreff

Michelle writes:

Let’s talk about gravity. I have been made keenly aware of this force for the past 40 hours because my equilibrium is out of whack and I am seasick. Here are some fun ways gravity is proving to be a whole new experience aboard the Gould.

  1. The stairs either rise up to meet me, or fall out beneath my feet.
  2. I have to time when I open doors, otherwise I am fighting a losing battle.
  3. I am suddenly walking on both sides of the hallway.
  4. I watched an orange roll back and forth across the mess hall floor.
  5. Getting out of the top bunk can be a lesson in being a ninja … or I can just fall out.
Watch a movie here while feeling sick

Watch a movie here while feeling sick

Apart from being sick, I am enjoying the ride. And even the sickness has dissipated thanks to some new medication. Moreover, everyone is really helpful in trying to get a fellow passenger cured. Amy (one of our senior scientists) checks in to make sure I am doing okay. Amelia (my advisor and the chief scientist for this cruise) let me crash in her room because it is more centrally located, unlike mine, which is near the bow. And Tasha brings me food from the dinner or lunch I may have missed. This just goes to show we truly are a little community. It’s hard to feel too bad when you have people looking out for you.

Work out here while feeling sick? (Not recommended.)

Work out here while feeling sick? (Not recommended.)

Okay, enough pity party, here’s what’s new. Continue reading

10/29/2013 – Ship Life

Tasha writes:

Ship life appeals to a person with a sense for adventure, the outdoors, and physical work. These are some reasons why some people thrive on going to sea:

  • You often set sail to some new or exotic destination.
  • The work schedule is maybe six weeks on with about two months completely off.
  • It’s incredibly peaceful when you have beautiful weather or when the ocean is so still it looks like glass (on very rare occasions).
  • Especially if you love the water, it’s nice to find a cozy steel hideaway out on the weather decks (outside) where you can sit and look out on the horizon, watch the water splash out from the ship, and watch the waves roll by. It’s mesmerizing.
  • Nothing compares to the sunrises, sunsets, and starry night skies out on the open ocean.
  • No cruise is ever the same so life stays exciting.
First hero shot of LMG13-11: Michelle enjoys the view from the 03 deck

First hero shot of LMG13-11: Michelle enjoys the view from the 03 deck

Things I don’t particularly enjoy about going to sea:

  • Bad weather. Seasoned veterans find rough seas and being able to walk on the bulkheads (walls) fun, but bad weather can make me absolutely miserable at sea. I get seasick and the Drake Passage crossing to get to the Antarctic Peninsula tends to have some of the roughest seas in the world so I, like many others onboard, stay in my rack (bed) for most of the days with rough seas until I get my sea legs (get used to the motion and stop getting sick). It’s very difficult to get any work done. Continue reading

10/28/2013 – Rockin’ and Rollin’: Entering the Drake Passage

Michelle writes:

Today we sailed down the Atlantic coast of Argentina and were treated to some spectacular views. When were close enough to the coast, we could see the land known as Tierra del Fuego (Land of Fire). From what I can see these are jagged islands capped with snow. To me, they look like something out of a Tolkien novel. It was sunny all day so the water is a deep sapphire blue. It was also warm enough to go out in a light jacket and many people took advantage of the weather to sit outside and read a book, or take some pictures.

One does not simply *sail* into Mordor

One does not simply *sail* into Mordor

Our days are not too busy yet. This leaves time for leisure: reading, watching a movie, playing a game, or just talking. A lot of the talking happens in the mess area where we eat.  In talking to crew and scientists, I am finding that people come from all over the United States (and the world, for that matter) to work on the ship or at the Antarctic Stations. I have met people from Maine, Texas, Colorado, and New York to name a few places. Not only are these people from different places, they also travel to many different places. Some of the MT’s (marine technicians) I talked to today spend part of their year in Antarctica, then go up to places like Canada and off the coast of Africa for more work. Everyone I have had the pleasure of talking to had an interesting story to tell, which makes our dinner conversations lively.

The swell is picking up down here. There is a noticeable increase in the rolling as we passed between the tip of Argentina and Isla de los Estados (in English: “Staten Island”). Continue reading