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Month: February, 2012

A Study of the Galley

If it isn’t the seawater sampling that structures our waking hours, it is definitely the galley. The galley is a maritime term for the kitchen, and it is where our two chefs, Jay and Richard, cultivate the cuisine of the cruise. Meals on the Revelle – not science stations – were the first indication that my ship routine would be different from my routine on land. Breakfast is at 07:30, lunch is at 11:30, and dinner is 17:00, all much earlier than when I usually dine at home. No matter how erratic our hours may be under the chemistry hoods or out on deck, these three meals serve as times to coalesce the entire crew, whether the breakfast of one is the dinner of the other, or whether the dinner of the early-riser is the mere afternoon snack of the latecomer.


I applaud the galley’s sympathy towards vegetarians. Surprisingly, there are only two of us. More surprisingly, they are both named Sara(h) (I am one of them). Here, we are recognized at lunch with our own tray of veggie burgers.

The food stock on board is a testament to the distant harbors that the Revelle has touched in its recent past. The true traces of its history lie beyond the obvious stashes of ice cream, pretzels, peanuts, tea, cereal, peanut butter & jelly, etc., which go fast. They are in the subtleties of the mess hall (i.e., dining area). At 7:30 am, they are in the heaps of freshly cut mango and pineapple hailing from the subtropics of South Africa. At lunch, they might be the produce in the salad. And, 24 hours a day, they are the uppermost jars on the snack shelves containing spicy, salty and sweet dried fruits from Thailand. As long as the food does not begin to spoil, our cuisine on board is a mix between the comforts of America (for example, tons and tons of peanut butter jars) and the local delights of international stops.

Aside from serving three timed meals a day, our chefs have also become the keepers of long-term time. They recall the passage of weeks by celebrating the long tradition of Sunday steak dinners. We have had two so far, the second of which marked one week at sea. At the centerpiece of these special meals are steaks that have been grilled to varying degrees out on deck; accompanying them are crackers, fine cheeses and, most pleasurable of all, cans of (non-alcoholic) ginger beer. Our second Sunday also featured Sunday-night tofu curry for the vegetarians. Thankfully, like any properly functioning culture, tradition is always open to evolution.

Finally, the food itself will begin to mark the passage of 35 days at sea. Our chefs are in a constant race against the clock, to serve the food before it goes bad. We still enjoy fresh fruit every morning and a nice salad bar for lunch, but the recent surge in banana bread for dessert suggests that bananas have become the first casualties in the fresh produce department. One might just be able to appreciate the procession of time by noting how the ratio of canned to fresh food will shift in the near future. It will then be up to the creativity of the galley to change the pace of time itself.

Close to Land, Not Close to Landing

Sunday, February 26 was a belated celebration of one week on the Revelle. The waves have undulated from less than 10 feet to more than 20 feet to less than 10 feet again, from green to blue to gray to blue, while our bodies have undulated between fatigue and energy, between faint seasickness and sharp clear-mindedness.

With one week behind me, I recall how the more experienced travelers on board have recounted to me what five at-sea weeks might feel like. Some statements have been contradictory. There are those who are wary of being with the same crowd of people for 35 days, and they forecast that five weeks will take a special toll on social tolerance. At the same time, however, there are some that are all the more optimistic that we will remain a cohesive and bright group. For now, I agree with the latter; we make a good group of thinkers, talkers, laughers, jokers, doers, eaters, cleaners, helpers, problem-solvers, teachers, students, and friends.


Numerous birds landed on the water beside the Revelle as we skimmed past the Crozet Islands in the Southern Ocean.

I have noticed, however, one statement of consensus among the seafaring experts. By the end of week 5, they say, you will want to get off. I can believe that. The need to stretch your legs on anchored land, on a ground that isn’t swaying, must be innate for those who come from the terrestrial animal kingdom, which happens to be all of us. And the cardio gym that we have on board cannot replace this desire for level space; it is hard for your legs to forget that you are on water when you are on water.

Almost as a test of one week’s endurance, the Revelle was very close to land today, the closest we have been since we first departed Durban one week ago. They were the Crozet Islands of the Southern Ocean, discernible by binocular and only through sheets of atmospheric haze to be a mass of angular rocks on the sea. The islands are likely uninhabited by people, making our vessel the closest human population. Yet flocks of seabirds—mainly albatrosses and petrels—gathered around us as we set up station, hinting at some community of wildlife that these nearby islands might harbor in the austral summer. But we focused on the water, not the land. We stayed on the Revelle, collected a lot of seawater, and did very rewarding research.

We will pass at least two other island clusters over the next four weeks; perhaps then we will feel a greater need to land and stretch our legs.

Keeping the Glass Half Full

Braving the elements is one rite of passage to becoming an oceanographer. I discovered this generational tradition yesterday as I helped Phoebe and Dan, my research team, sample our last subtropical station of the western Indian Ocean. The Revelle was passing through a storm, a low pressure zone of the ugliest character: grey thundering skies, sheets of rain, deafening wind and frothy wave crests crashing over our rubber boots on deck.
Studying the ocean is a delicate balance between organization and improvisation. On one hand, the science crew on board follows a strict schedule of sampling and in-lab testing. For example, my group takes ocean samples about every other day; our time is split between preparing for these sampling stations as well as doing immediate chemistry on the seawater we collect. With just 5 weeks on board, we aim to collect and process roughly 300 samples of seawater particles to measure carbon and thorium. About 18 hours in the day are utilized cumulatively among the three of us to get this done.
At the same time, the sea changes constantly. The size of the waves from Durban until now has probably doubled (grip pads are now on every meal table!), and last night the temperature dropped drastically as we descended southward in latitude. These changes are foreseeable, but there is always an element of uncertainty as the Revelle plows through mountains of waves and different weather zones. Fast decision-making is equally necessary for the organized scientist.
Dan says casual whistling on a ship always jinxes something, so that most likely explains why the storm picked up just as we deployed our first instrument into the water. The instruments we lower are heavy battery-powered pumps programmed to pump high volumes of water through a labyrinth of plastic tubing. At the end of these tubes are large filters that collect the solid particles suspended in seawater. Ultimately, Phoebe, Dan and I will measure the metal content, carbon content and thorium radioactivity in these particles.
Considering the weight, price and academic value of these pumps – not too mention the futility of our rubber boots against the wave crests – there were several risks in descending eight of them on a Kevlar wire. As the weather worsened, we were forced to abandon the cast, though thankfully not to abandon ship. We deployed a quicker CTD cast shortly after, as a last-minute make-up for our losses. But the CTD rosette collects at most 360 liters of unfiltered seawater at a given depth, while each pump alone filters two to three times that volume underwater, leaving us with only half the intended volume at one of the eight intended depths. Fortunately, improvisation has its way of keeping the glass half full even when crazy waves are trying to topple it over. At the end of our day, that was one less data sample lost to the elements.

weather change

Change in the Weather

It is fascinating how quickly weather can shift at sea. The Revelle crew keeps tabs on these changes and posts them online. Here is a graph of the changes that occurred from 6:51 AM February 23 to 6:51 AM February 24. As the red line shows, the air temperature descended about 10 degrees Celsius from late afternoon to evening February 23. This coincided with crossing a weather boundary called the sub-Antarctic front. From now on, we should expect colder temperatures and colder waters.

Cold Waters Run Deep

At midnight in the Indian Ocean (037°29.8’ S and 039°58.6’ E) on February 22 I touched the coldest seawater I have yet encountered on this trip–about 50 degrees Fahrenheit. By cold, I mean relative to the shallow, subtropical water I have thus far handled at our one other collection site (a little below room temperature), as we have not ventured too far south towards Antarctica yet. This midnight collection retrieved waters from 2500 meters (~1.5 miles) below surface.

Rumors among the science crew suggest that this was North Atlantic Deep Water (NADW), a seawater mass famous among oceanographers for its long, meandering path and its role in the global climate system. In fact, if you aren’t an oceanographer but have at least studied general environmental science, you might have read about this water mass. NADW is indeed famous because it helps transport heat to the North Atlantic, effectively regulating global climate patterns across the Northern Hemisphere.


The CTD is connected to a rosette of 12 bottles that collect seawater at various depths.

One fascinating fact of the ocean is that even the subtlest differences can cause striking patterns. Just as one off-beat drummer may shift the entire rhythm of the marching band, small differences in saltiness or temperature of seawater shift movements in the entire ocean. Amazingly, these slight variations become global patterns that govern climate, weather and can even affect the movement of one accidentally discarded soda bottle as it drifts across the ocean. North Atlantic Deep Water is a phenomenon of such proportions. It originates as surface water in the North Atlantic, which sinks to the deep because it is colder and saltier than surrounding water. Once in the deep, NADW flows south and then east before welling up again in the Indian and Pacific Oceans and eventually returning to the Atlantic, making it one of the largest seawater migrations on Earth. This extensive path enables oceanographers even in the Indian Ocean to encounter this abyssal treasure.

Meeting deep waters is not a simple task, but oceanographers have fine-tuned ways to collect them. A common way to do it is through a “CTD cast”, as we do on the Revelle. CTD stands for conductivity, temperature and depth; suspended from a wire, the instrument it describes physical characteristics of seawater (conductivity, temperature and depth–hence the name) as it travels beneath the surface. CTDs do not collect the water themselves. This is the job of the rosette attached to the CTD. The rosette comprises a ring of 12 bottles—each a little over half my height—that collect seawater at target depths. As the bottles (actually tubes with caps on either end) descend in open position, a diligent observer sits in front a computer and, at proper depth, sends an impulse for one bottle to close, capturing a seawater at that location. Early yesterday, after 3 hours and thousands of meters of underwater travel, the Revelle science team had its own collection of deep water on board.

Ode to Cargo Straps

On a ship’s hallways, the shortest distance between two points is a zigzag. The Southern Ocean harbors the tallest waves of the open oceans; so here on the Revelle, it is common to walk into a wall when traveling its narrow hallways. One of the shipboard engineers told me that during the roughest conditions, they ballast the ship so that it stays upright instead of swinging 20 degrees side-to-side.


Beta detectors secured underneath hundreds of pounds of lead and tight ratchet straps.

On a turbulent vessel, there is a lot that goes into planning how to study chemistry, or almost any other precise science. Things that are normally harmless on static, level ground become dynamic actors on the chaotic drama of the ocean. Living on a ship means that you have to look at every object and think: can it roll? Can it pop? Can it fly out of control towards disaster?

Thankfully, years of experience and creativity have equipped vessel-borne scientists with trusty solutions to the risks of wave-action and gravity. Before leaving port in South Africa, we spent three days securing every glass bottle of corrosive liquid onto the walls and tables with Velcro or packing tape, fastening every instrument to its surroundings with rope and bungee cords. These labors come with peripheral rewards. I’ve taken away (1) the knowledge of two strong knots and (2) a new vocabulary of construction hardware.

My most essential research instruments tethered on board live beneath several hundred pounds of lead, and one strenuously tight ratchet strap. They are called beta detectors (see photo), and they measure the radioactivity of a natural element in seawater, thorium-234. My interests in ocean carbon have led me to the subfield of thorium chemistry, which uses these radiation measurements to trace sinking carbon in the sea. When measuring radiation in beta detectors, lead ensures that I get only the radiation I want. Just as lead vests block harmful X-rays at the dentist’s office, the lead brick house around my detectors blocks any outside radiation from interfering with what I measure inside. This way I know that the radiation I measure comes from seawater and not from the computer screens and light bulbs around me. This this lead tower is perhaps one of the most precarious constructs in this laboratory, but its sheer weight and strenuously tight ratchet straps makes these beta detectors the most secure as well.

Of course there is a lot more to living in constant motion, for not all aspects of life are science, even for field oceanographers. Every time you might ask how the Revelle could possibly hold itself together, there is almost always an answer. That answer could be small hooks behind every bathroom door, the anti-slide grip pads under warm pans of dessert in the mess hall, the small lock features on all things that open and close. Altogether these seemingly simple constructs are ingenious innovations that make the ship habitable, that make the culture of sea-travelers viable. One cannot take the subtle architecture of the Revelle for granted.

Leaving Port

The Great Calcite Belt is a particularly reflective region of the Southern Ocean, seen as a distinctly bright band encircling Antarctica. Some scientists (not all) believe that high amounts of calcite (the same mineral in coral) in the surface ocean cause it to appear as it does. Hence, the Great Calcite Belt lies somewhere between idea and proof. The belt itself undoubtedly exists, but the calcite that it produces remains the scientist’s test.


Leaving the port of Durban, South Africa, the soccer stadium that hosted the 2010 World Cup is one of the last landmarks of the city you can see as you enter the open Indian Ocean.

From now until March 23 a crew of scientists and ship engineers will traverse the Southern part of the Indian Ocean to investigate the existence of the Calcite Belt. My role in this expedition is carbon, arguably one of the most sought after elements in the history of industrialism and environmental advocacy. While humans have pumped massive gigatons of carbon dioxide into the atmosphere for the last 150 years, ocean biology has re-absorbed a fraction of it into its own mass. Like plants, marine plankton at the sea surface breathe in carbon dioxide and store the carbon in their own bodies. They die. They get eaten by bigger things. They sink deeper. The plankton-borne carbon that actually reaches the deepest parts of the ocean stays locked up for hundreds to thousands of years, unable to act as a greenhouse gas in the atmosphere.

For those concerned with the warming climate, the fraction of carbon dioxide that is soaked up by ocean biology is an important number. I spent much of my college years learning about the updated estimates of this number, but also found that with the sheer size of the oceans, new sea measurements add unique pieces to the puzzle. What new pieces will this ocean venture on the Roger Revelle bring? How may the existence of a calcite belt in the Southern Ocean affect sinking carbon in this region? How can observations from one cruise track in one part of one ocean basin influence traditionally global perspectives of ocean carbon?

Other questions that I will investigate over the next five weeks are:
-How can I learn to salsa dance on a boat?
-If I am a good ping-pong player on land, does that mean I am an equally good ping-pong player on the ocean?
-What foods will I miss most being away from my terrestrial home?
-What is the best way to remember how to tie a knot (so far, my educated hypothesis is that three different teachers is most effective).

Through these weeks on the Revelle, some questions will be answered better than others, while some questions may prove feasibly impossible. I may never get to practice salsa dancing, for example. But, if I secure a few hours on the ping-pong table in the main laboratory, I may just have enough results to report.