The Story Beneath the Sea
A scientist, an expedition, and contemplating climate change from the bottom of the ocean.
Text by Jennifer Sutton and Emily Estes ’06
Photographs by Sarah Kachovich
Last November, marine chemist Emily Estes ’06 stood on the deck of the R/V JOIDES Resolution, looking out at the vast South Atlantic. The ship was positioned about 1,000 miles off the coast of Brazil, where the water is “stunningly clear,” Estes wrote in the ship’s log. “When the sun is out, shafts of light can penetrate tens of meters and make the water radiate an almost purple-blue. Gazing at it is addictive.”
But Estes wasn’t aboard the JOIDES Resolution to gaze at the sea. Most of her attention was directed several miles down, beneath the ocean floor. She’s a staff scientist and expedition project manager for the International Ocean Discovery Program (IODP) based at Texas A&M University, and she was halfway through a two-month research trip along the underwater Mid-Atlantic Ridge, part of the longest mountain range in the world.
The IODP and the JOIDES Resolution embark on several expeditions every year, bringing together paleoceanographic researchers from around the world. With equipment similar to that used in the oil industry, the ship’s crew drills samples of sediment, or “cores,” from deep in the Earth’s crust. The core samples help document how the planet and oceans have changed over millions of years, and predict how they might change in the future. Water currents and temperatures, mineral deposits, the evolution and extinctions of marine life — it’s all there in the cylinders of rock that get hoisted to the ship’s deck.
“Expedition project manager” means that Estes is the liaison between the academic researchers who study the core, and the engineers and technicians who do the work of collecting it. Because of COVID restrictions on the number of people who could board the ship in 2020, no visiting scientists were permitted to join this particular IODP trip. They’ll return, with Estes, in 2022, but for those two months at sea, it was Estes’s job to “ensure that our operations achieve their scientific goals as much as possible.”
As the JOIDES Resolution, or JR, transited from Kristiansand, Norway, to Cape Town, South Africa, Estes kept a journal in addition to the official ship’s reports she was charged with writing every day. The handful of entries she shared with NMH Magazine offer a glimpse into what it takes to contemplate climate change from, literally, the bottom of the ocean.
October 5, 2020
The crew arrives in Kristiansand more than 24 hours after leaving Texas. We immediately begin a strict quarantine, and a little paranoia sets in: Is that jet- lag-induced fatigue or COVID-19? The pandemic has pushed us into uncharted territory, like every other workplace. But we’re an organization that excels at logistics. We always have multiple contingency plans.
October 9, 2020
After boarding the JR, we spend the first few days navigating around rocky islands covered in conifers and lighthouses, crossing the North Sea, and going through the Strait of Dover at sunrise. The White Cliffs of Dover are particularly famous among oceanographers — they’re composed of the fossilized remains of coccolithophores, one of the microscopic fossils commonly used by researchers to reconstruct past climate conditions on Earth. Seeing the cliffs of Dover is the oceanographic equivalent of seeing a celebrity. We gather on deck to snap selfies.
Estes is a chemist, and she’s interested in what’s happening on a cellular level within the core samples that the JR extracts — “what microbes are doing in really extreme environments,” she says. Microbes may be tiny, but if enough of them do the same thing, they can affect the entire planet. Think about photosynthesis as an example, Estes says. “In the ocean, billions and billions of tiny cells are all doing the same process and creating half the oxygen on Earth.”
When the JR gets to its research sites — there are six — the crew spends about a week to 10 days installing “re-entry” systems in the sediment. These are long pipes topped with giant funnels that enable a drill to penetrate nearly 600 meters of sediment to the basalt oceanic crust below.
October 17, 2020
During the 6,600-mile transit to our first research site, we keep busy. We re-program software, re-plumb gas lines, re-calibrate instruments, inventory ship supplies. The logging engineer teaches a basic Arduino programming workshop, and we make colored LEDs blink and tinker with pressure sensors. It’s fun, but it will also help us when we’re maintaining shipboard instruments.
October 21, 2020
It’s been two weeks since our last possible exposure to the coronavirus, and we are free to relax our risk-mitigation protocols. We all feel a huge, joyful relief. But it’s surreal and sobering to exist in this COVID-free bubble while across the globe, cases are surging.
Estes grew up in landlocked Buckland, Massachusetts, not particularly drawn to science. She spent a lot of time outdoors as a kid and “could stare at a stream for hours,” but was more interested in writing and playing the electric bass. At NMH, she took Becca Malloy’s AP Environmental Science class, and later traveled with students and teachers to New Zealand, where she was fascinated by the landscape. She thought about becoming a journalist so she could write about environmental issues, and at Wellesley, she initially declared a major in environmental studies. But during a geology class, she had an epiphany: “There’s so little we actually understand about how environmental and geological processes work in the world,” she said.
“Because so much remains unknown about the ocean, even getting what you expected can be surprising and delightful.”
Captivated by “the interface of geology and public health,” Estes finished college as a geosciences major and got a job researching contamination from a former mining site in Oklahoma. She also worked in Boston, testing lead content in urban gardens. “We could say, ‘Grow your plants here, don’t grow your plants there.’ I liked being able to have a clear guideline to give people that was helpful.”
Estes started graduate school at MIT thinking she would study soil science. But early on, she got a chance to join an oceanographic research expedition in the Pacific. Over the course of three weeks, she “completely fell in love with being at sea.”
October 21, 2020
Overnight, we arrive at our first site. The ship transitions from cruise mode to dynamic positioning mode, which automatically holds us at our exact GPS coordinates. The change in motion was subtle but enough to wake me up, and I was too excited to go back to sleep. It took most of the day to assemble and lower the drill pipe to the ocean floor 5,006 meters below us. Even with modern technology, it’s difficult to determine the exact depth. But we were successful. We did not miss our target and collect a “water core” by mistake.
I stayed up late to see the first core pulled back to the surface. It arrived on deck at 11:35 pm. The coring crew helps the technicians pull the plastic core liner and the nine-meter-long sediment core itself out of a metal barrel, and the technicians launch into their well-rehearsed routine of documenting the core’s length and voids (holes) and cutting it into sections to bring inside the lab.
The sediment is beautiful, alternating layers of reddish-brown pelagic clay and white carbonate ooze. It’s what we expected, but with deep-sea research — because so much remains unknown about the ocean — even getting what you expected can be surprising and delightful.
The sediment is a little like the rings in a tree trunk — a record of natural history. Scientists can reconstruct what the seawater temperatures were, and how rapidly the oceans heated or cooled, and what the salinity of the ocean was at different points in time. They can see, through fossils in the sediment, when entire groups of organisms went extinct. “All of these things are interwoven,” Estes says.
Remember how Estes studies microbes? Specifically, she studies the organic carbon in the sediment, which the microbes eat. (It’s how they survive a kilometer deep in the Earth under five kilometers of water.) But if the carbon is too strongly attached to the mineral surfaces of the sediment, the microbes can’t get to it. Estes tries to quantify how much organic carbon has been preserved in the sediment for millions of years, and how much gets eaten. These microscopic interactions are part of a much bigger oceanographic question: What are the most extreme conditions in which living organisms can survive? In other words, “what is the limit of life?’” Estes says. “Scientists actually use these sediments as an analogue for what life might look like on other planets.”
November 10, 2020
Watching something go as planned brings us a sense of satisfaction and adrenaline. We’re at our second site now, and this morning, we deposited a re-entry system on the seafloor. When we return to the site in 2022, we’ll be able to re-enter a hole we have already partially drilled and quickly drill into the basalt oceanic crust underlying the sediment.
We use a drill bit to penetrate the sediment and an underreamer that follows the bit to widen the hole. We then lower in a string of wide-diameter pipe called casing that will hold the hole open, topped by a large funnel that sits on the seafloor. The funnel is so large that in order to deploy it, we have to open up the doors of the “moonpool” in the center of the ship and slowly lower the funnel through the “splash zone.” Everyone on board who is unoccupied dons their hard hats, safety goggles, and work boots to come observe this operation.
As the moonpool doors slide open, vibrant blue light fills our eyes — sunlight refracting through the intense blue of the ocean. The funnel is lowered through the moonpool, the waves frothing as the funnel hits the water, then calming again as the funnel disappears into the depths. The moonpool doors close, and we trickle back to our jobs, buoyed by the progress we’ve made today.
“We’re looking at events that happened 10 million years ago in order to think about what might happen 1,000 years from now.”
The research Estes and other IODP scientists do is long-term. “We’re looking at events that happened 10 million years ago in order to think about what might happen 1,000 years from now,” she says. It’s the opposite of the soil-contamination research she did early in her career. “I’m okay with that,” Estes says. “But it’s one of the things that’s hard for people to grapple with when they’re getting into sciences — finding your work meaningful when you’re not able to see it immediately pan out.”
November 28, 2020
We’re at our easternmost site, closest to the Mid-Atlantic Ridge, where the underlying basalt basement is young (only an estimated 6.6 million years old!) and covered by a thinner layer of sediments because there’s been less time for them to accumulate. The water is also shallower, only 3,055 meters deep, which decreases the amount of time it takes our coring equipment to get to and from the seafloor. The days become a blur. We trip pipe to the seafloor, get core on deck within a few hours. Recover the drill pipe, and deploy our final re-entry funnel and casing string to the seafloor.
We’ll revisit these sites to core more sediment and drill the basalt with a group of scientists, so this trip, without them, was a unique opportunity to learn more about the limits of our tools. We could take time to problem solve and troubleshoot without a large group of people itching to accomplish their research. We were lucky to be able to make the best of unfortunate COVID circumstances.
December 5, 2020
We arrive in Cape Town: gorgeous weather, a few harbor seals, and a spectacular view of Table Mountain. The feeling is bittersweet. I’ve missed fresh vegetables, my dog, and my partner. After working 12 hours every day, my most intense desire is to wake up after sunrise. But disembarking also means we will be transported back into the pandemic. The thought of staying in our little bubble is, selfishly, appealing. But it’s time to crew-change. Another group is waiting to board the ship and accomplish their own bit of science.