Pranaykumar Tirpude, a doctoral candidate in the Department of Earth Sciences studying paleoclimate, is pictured onboard the R/V Roger Revelle.

Researching rare earth elements

Article by Adam Thomas Photos courtesy of SEALS team and Tony Rathburn September 15, 2025

UD part of large, multi-institutional expedition to the Labrador Sea to study sources and sinks of REEs

Rare earth elements (REEs) are becoming increasingly important in electronic gadgets used in day-to-day life, yet the natural sources and sinks of REEs are largely understudied.

In the summer of 2025, a group of researchers from the University of Delaware co-led a research expedition to the Labrador Sea to quantify the amount of REEs that come out from the ocean bottom. The five-week-long expedition, the Sediment Exchange Along the Labrador Sea (SEALS), was supported by the National Science Foundation (NSF). Other than UD, participants from 11 institutions were involved onboard the Research Vessel (R/V) Roger Revelle.

During their time in the Labrador Sea, located in the North Atlantic Ocean between the Labrador Peninsula and Greenland, the UD team sampled ocean bottom sediments, seawater and suspended particulates. They gathered critical water and sediment samples and led a series of educational activities for classrooms throughout the world as part of a ship-to-shore outreach program.

The scientists and crew on the SEALS expedition.

The team from UD included Chandranath Basak, assistant professor in UD’s Department of Earth Sciences; Evan Borodin, an undergraduate honors student with a double major in Environmental Science and Marine Science; Cory Hite, a doctoral student studying marine geochemistry; and Pranaykumar Tirpude, a doctoral candidate studying paleoclimate.

In addition to looking at REEs, Borodin was able to work on his own undergraduate research project, which revolves around collecting stable carbon and oxygen isotopes from the bottom water and porewater along the Labrador Sea.

“My research goal is to use these stable carbon and oxygen isotopes to construct a calibration curve that will be used as a proxy for bottom water oxygenation,” Borodin said.

The UD research team is pictured. From Left-to-Right Evan Borodin, Pranaykumar Tirpude, Chandranath Basak, Cory Hite.

The UD research team, (left to right) Evan Borodin, Pranaykumar Tirpude, Chandranath Basak and Cory Hite.

Basak, who served as a principal investigator on the expedition, said the goal was to collect samples to investigate if and how much REEs are being released from ocean-bottom sediments.

“We want to quantify the flux of REEs from the ocean bottom,” Basak said. “To achieve this scientific objective, we collected short sediment cores using a device called a multicorer and extracted the water residing in the pore spaces of the sediment. This water is called porewater, and we will measure its concentrations to estimate how many REEs are reaching the ocean from the sediment.”

Once the samples were collected, preliminary analyses were completed onboard the research vessel, but most will now be analyzed at UD and other collaborating institutions. UD samples will primarily be analyzed by Hite as part of her doctoral dissertation research.

Ship to shore

Hite led 10 ship-to-shore sessions along with other scientists onboard the ship. During these sessions, they connected with various classrooms and teachers, giving the students a sneak peek into how the team of oceanographers studies the ocean. They showed the instruments used, the labs they work in aboard the research ship and answered any questions.

“Through these ship-to-shore sessions, we aimed to inspire the next generation of students and young minds by talking about ocean research and its real-world relevance,” Basak said.

Cory Hite (right), a UD doctoral student in the Department of Earth Sciences studying marine geochemistry, and Cassandra Bartels (left) of the Woods Hole Oceanographic Institution conduct a ship-to-shore session.

Research experience

The UD participants all said it was great to work onboard the R/V Roger Revelle and to collaborate with scientists from other institutions.

“We had both a great science party and crew,” Hite said. “Everyone was collaborative and supportive of each other, which I think was part of what made the expedition so successful. It was such a unique experience to work alongside scientists at all stages in their careers — from undergrads to professors, and from all over the world.”

They also pointed to the importance of continuing scientific research out on the open ocean. Tirpude added that the role of the ocean is central to helping humanity.

“Oceans regulate climate on multiple timescales, and disruptions to ocean circulation, caused by glacier melting and warming, can have far-reaching consequences,” Tirpude said. “Research expeditions like ours help us understand deep ocean circulation and its role in climate regulation. By studying past and present changes, we can better predict future climate behavior and make informed decisions.”

A multicorer was used to collect short sediment cores. Researchers extracted the water residing in the pore spaces of the sediment. This water is called porewater, and researchers measured its concentrations to estimate how many rare earth elements are reaching the ocean from the sediment.