Friday, October 1, 2010


Station 17
36° 41.372’ N, 73° 28.074’ W
02:20 EST
Winds: 37 knots, gusts to 45 knots
Sea Surface Temperature: 73°F

We are situated at the convergence of a tropical low-pressure center migrating Northward and a cold front marching Eastward. They act in concert to pitch 40 knot winds and 18 foot swells. We are rocking, cabinets are creaking, and waves intermittently slap the iron hull like cars hitting a barricade. We are holding station and our work is on hiatus. We only have a few days left to complete a rather ambitious agenda: 2 kilometers of sediment traps, multiple CTD casts, in situ pumping casts, and sediment coring.

When weather gets rough like this, the science party has three primary concerns: 1) securing samples and gear, 2) helping each other as needed, 3) and considering contingency plans that will maximize the scientific value of our limited time at sea. After that we can rest, lay down, and watch a movie while riding out the storm. We are lucky.

The crew of Atlantis is not. They do not go on hiatus when the seas are rough. Whether in the heat of the engine room or high on the bridge, they continue to keep us safe, healthy, and productive. Without them, oceanography would be purely theoretical. For all this and more, we are grateful to the crew of the R/V Atlantis. With their help, our science objectives will be met before steaming into port on Tuesday.

* For real-time marine conditions near Station 17, visit NOAA's National Buoy Data Center, Station 41001

Tuesday, September 28, 2010

Under Pressure

Station 15
34° 38.463’N, 71° 29.960’ W
14:25 EST
Winds: 8 knots
Sea Surface Temperature: 82°F

We arrived at Station 15 yesterday under clear skies, over blue water, and through strings of bright yellow sargassum as long as our ship. Flying fish soar through the air (occasionally onto our deck) and sea spray encrusts our gear with coarse grains of salt. The sun is shining today on the deepest station of our final transect across the continental slope. The remaining stations will take us ever closer to our homes.

Although the transit to Station 15 offered several hours reprieve from sampling, it did not relieve us from sample processing. For example, WHOI’s Paul Morris is examining the distributions of Radium and Thorium in seawater. One of four isotopes of interest, Radium-224, has a half-life of 3.66 days and will decay to an undetectable abundance within weeks of sampling. If it isn’t measured now, it won’t be measured at all. Katherine Hoering and Kristin Luttazi have been quantifying the abundance of dissolved inorganic carbon (“DIC”, think baking soda dissolved in water) around the clock, trying to keep pace with influx of newly retrieved samples. Other scientists, such Drew Snauffer from the University of British Columbia, have been preparing their samples for long-term storage by filtering and acidifying large-volumes of water (20 liters each). Long hours, intermittent sleep, and focused work are essential to the success of this very expensive endeavor.

Amid the rush to complete our tasks, we do find time to decompress. Our teams have been sharing many laughs, songs, movies, and good meals (have I mentioned how good the food is?). Morale is high, thanks largely to our chief scientist, Tim Eglinton, and the tremendously supportive crew on Atlantis. Our spirits are also indebted to the juxtaposition of our innate curiosity about the natural world and oceanographic traditions. For example, have you ever wondered what the weight of the ocean could do to a Styrofoam cup? The tiny air pockets are no match for the pressure at 4500 m depth (deeper beneath the waves than the summit of Mt. Whitney rises above sea level) and the cup is squeezed into a distorted miniature version of itself (see photos of a cup before (above) and after (below) traveling to the bottom of the sea aboard our CTD). What kinds of life can exist under such extreme pressure? How does it affect the chemical composition of the sea? How sensitive is it to change over geologic time scales? Questions like these drive our work. Camaraderie, this incredible environment, and Stryofoam cups help us endure the pressures.

Sunday, September 26, 2010


Station 14
37° 41.713’ N, 68° 28.402’ W
04:19 EST
Winds: 19 knots
Sea Surface Temperature: 80°F

The CTD was in the water and we were in the computer lab operating the winch. Kilometers of wire unspooled on a video monitor and data streamed across our computer monitors. At night, against the backdrop of a black sea, Atlantis’ machinery appears to float in empty space. But not tonight. Something was different. Something barely perceptible on the video monitor was moving outside. Something big. I opened the door and walked onto the back deck. The ship’s frame obscured my view. I walked further and turned around. And there they were. Three giants reflected in the water.

There is nothing quite like moonlight on a calm sea. The bright light of a waning gibbous beamed silver ribbons across the waves from the horizon to our ship. It was being chased by a deceptively small but unusually bright companion. Not quite large enough to burn with the nuclear fires of sun, but presently close enough to reflect ample light, this bright “star” was actually the planet Jupiter. Together, these two giants wandered peacefully across the sky, looking over us while another giant wandered beneath us.

If we look beneath the shimmering moonlight, beneath the waves that batter our ship, we find a system of currents as wide as the Atlantic Ocean (which happens to be about as wide as the Moon). The strongest lies at the surface and is known as The Gulf Stream. This mighty current wanders along the North American margin, carrying warm water from the tropics to colder northern latitudes. It is one of the primary reasons why London’s climate is milder than the more southerly New York City. It is also easy to see why this is the case: the sea surface temperature is 80°F today. This is in stark contrast to the frigid bottom-water temperature of 35°F. Clearly, the system of currents that runs through the deep is complicated. The speed, width, depth, and locations of these currents have been observed to vary seasonally. They surely have varied on much longer timescales as well. What is certain, however, is that they carry more than water and heat. Like rivers running through the landscape, currents carry the physical, chemical, and biological fingerprints of their source waters. That is why we chose to study this site. Particle transport associated with ocean currents needs to be untangled before we can understand how our planet works. In addition to radiocarbon, we are measuring the concentrations and isotope ratios of dissolved Oxygen, noble gases, Radium, Thorium, Protactinium, Neodymium, and dissolved lignin—tracers that allow us to compare the abundance of material transported horizontally by various currents to that raining down from above.

Today we leave Line W and move south toward Cape Hatteras for our third and final transect. With a little help from the wanderers below and illumination from the wanderers above, we will continue to read the message bottles of Earth.