Pilot whales, northern lights, breakfast every day overlooking the ocean—it sounds like a dream Scandinavian cruise, but not one you’ll find on any travel site. In 2021, geoscientist Sarah Lambart embarked on a scientific mission to explore the geologic history that shaped the continents as we see them today. That mission took her past the Arctic Circle aboard a research vessel equipped with a drill rig that pulled up sediment and rock cores from the deep ocean floor, giving Lambart and her colleagues an insight into volcanic activity on Earth 60 million years ago.
“This was an extremely successful expedition,” said Lambart, an assistant professor in the Department of Geology and Geophysics. “We drilled 21 holes and recovered more than a mile (about 2 km) of cores.” But with a wealth of information in the cores that are only beginning to be investigated, she said, “this is only the beginning.”
Coring the ocean floor—for science!
Lambart’s expedition was organized by the International Ocean Discovery Program (IODP), “an international research collaboration that coordinates seagoing expeditions to study the history of the Earth recorded in sediments and rocks beneath the ocean floor,” according to the program home page. In nearly a hundred expeditions on two scientific drilling ships, the program has explored the groundwater in the ocean floor beneath the Gulf of Mexico, the fault that produced the 2011 Tohoku earthquake and the history of the monsoon in the Arabian Sea, among many other scientific questions.
Lambart’s cruise aboard the vessel JOIDES Resolution was IODP Expedition 396 and sailed from Aug. 6 to Oct. 5, 2021. After departing from Reykjavík, Iceland, the ship stopped at 10 drilling locations off of the coast of Norway. As a petrologist (igneous rock expert), Lambart was part of the international scientific team that described and documented the cores of sediment and rock that the drilling rig brought up from the ocean floor.
The mission explored a geological event of excess volcanic activity associated with the breakup of North America and Europe and the formation of the North Atlantic Ocean, beginning around 60 million years ago. The North Atlantic break-up event generated a volume of magma that is too high to be explained by the type of volcanic activity that occurs along the Mid-Atlantic ridge today. Several processes can potentially explain this excess magma, but the relative importance of each remains unresolved. Soon after this enormous magmatic event, the global surface temperature rose by about 5 °C (9 °F). This event, called the Paleocene-Eocene Thermal Maximum (PETM), is probably the best ancient analog of modern climate change, but the link between volcanic activity and the PETM around 55 million years ago has yet to be established.
Sailing during the COVID-19 pandemic necessitated some procedural changes. Among the 27 scientists selected for the expedition, only 19 were authorized to sail to keep enough empty berths in case someone needed to be isolated. Additionally, before boarding the ship, Lambart and the other sailing members spent a week in a hotel in Reykjavík in strict quarantine. During the week, they met frequently via Zoom to receive ship and lab safety orientations, discuss the research plans and the drilling operations and engage in outreach activities to share their experiences. Lambart took to Twitter to introduce the world to Whatze, Claude, Gigi, Finn, Spinette and Halvard—six stuffed plush animals Lambart called the “quarantine buddies.”
“Carlos, the expedition project manager, advised us to bring something fun for distraction onboard,” Lambart said. “We were the first team of scientists going through this process before sailing and I thought it was interesting to share this experience. Also, I was in quarantine, so I needed distractions.”
The buddies, along with Lambart, watched lab safety briefings, took COVID tests and stood at the window to watch the JOIDES Resolution come into view for the first time. Then they joined her as she and her colleagues emerged from quarantine to finally meet each other.
“Waiting for the bus to bring us to the port was a bit surreal,” Lambart said. “Most of us didn’t know each other at that point, except for our interactions on Zoom the past few months.” After selfies at the port the expedition members, many of which had never sailed before, boarded the JOIDES Resolution and set off toward the Arctic.
Life at sea
As part of the five-member Core Description Team, Lambart worked a noon-to-midnight shift, documenting and describing the cores as soon as they came out of the drilling rig and were ready to be split, with one half of the core to be used for research and the other destined for storage in the IODP Core Repository in Bremen, Germany.
“I really liked being part of the Core Description Team because it is the only team that sees all the cores in detail!” she said. “We are the first to describe rocks that come from thousands of meters beneath our feet.” But, she added, the smell of drilling mud at the beginning of each shift was “not my favorite.”
To describe hard rock samples, the scientific team would prepare thin sections—slices of rock only 30 microns thick (an average human hair is 50 microns, Lambart said) and so thin that when glued on a glass slide and polished, they allow light through. When viewed through polarizing filters in a microscope, the various minerals in the sample show off a brilliant collage of colors. Petrologists can learn a lot about the history of the rock from the minerals present and their textures.
Because the scientific crew was smaller than usual, Lambart had to stretch beyond her geological comfort zone. Although an expert in igneous rocks, she also described and cataloged sediments and sedimentary rocks. That involved preparing “smear slides” for sediments that were soft enough, spreading the sediment over a slide with a toothpick. Under a microscope, smear slides can help researchers identify if sediments contain volcanic ash, a key science question of the expedition.
As the ship proceeded from one drilling site to another, the various scientific teams also regularly met to present their results.
“I really liked this part as those were really the moments during which we could see what each team was doing and discuss the results together. It was very satisfying to see so many disciplines including petrology, sedimentology, geophysics, paleomagnetism, geochemistry and palynology (the study of pollen and spores in geological records) work together to come up with a geological story that matches with all data collected on board. I rarely, if ever, have seen such multidisciplinary work being so effective.”
Outside of the lab, the two-month cruise settled into a routine. Dinner each Saturday featured a chocolate lava cake. Colleagues would sometimes play Ping-Pong at the end of a shift, although “Ping-Pong during heavy weather can be quite challenging.”
Whenever possible, Lambart made sure to spend her breakfast time outside. “Most of the time I was by myself, a few times, I was joined by others,” she said. “It was a very peaceful way to start our very busy days. Being able to contemplate the ocean as far as the eye can see almost every day for two months is an experience by itself.”
Unlike the mariners of previous eras who were completely isolated during their voyages, the passengers on the JOIDES Resolution kept in regular contact with the rest of the world. Scientists and IODP staff conducted virtual ship tours and live broadcasts with classes. Lambart participated in seven of these broadcasts, including three with the U’s Department of Geology and Geophysics.
“I posted on Twitter regularly,” she said, showing her stuffed buddies participating in shipboard activities, and received weekly reports from her research lab at the U. Her expedition was the first to feature limited internet connectivity on personal laptops, and the ship set up a dedicated Zoom station in the computer room.
“I was using the Zoom station every other day to chat with my husband after my shift, around 1 a.m.,” she said. “There was only one computer on board with Zoom access, so we had to schedule our personal and professional meetings.”
Apart from the scientific excitement of the core drilling, the sea voyage was largely uneventful until a large storm near the end of September.
“I never felt in danger during this storm,” Lambart said, “but we certainly all felt the 45-foot (14 m) wave that hit us. A lot of stuff fell on the floor, in the labs, in the kitchen.”
Just the beginning
Collecting the cores is really only the first step in answering the expedition’s scientific questions. Researchers will spend years studying the samples and exploring how the rocks and sediments they contain fit in with the geological history of the Atlantic Ocean basin. To begin, the members of Expedition 396 will reconvene in April in Bremen at the IODP Core Repository. They’ll collect the samples needed for their respective research programs. Lambart’s team will use the samples to try to determine the thermal and chemical conditions under which the igneous rocks formed.
“I am particularly excited about the prospect of continuing this multi-disciplinary investigation to determine the cause of excess magmatism (volcanic activity) during the Northeast Atlantic Continental Breakup and its potential link with the Paleocene-Eocene Thermal Maximum,” she said.
Although the expedition involved long shifts and a long stretch at sea away from family, Lambart would, and even hopes to, do it again.
“This is a unique scientific and human experience,” she said. “The multicultural aspect of this international program is probably my favorite part. I just wish I had done this earlier in my career. So my advice to the next generation of scientists is to not hesitate to apply!”
Learn more about the expedition’s scientific team and research objectives here.