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MBARI leads international expedition to study impacts of climate change on Antarctic seafloor

During a January 2026 expedition aboard the Spanish polar research vessel Hespérides, MBARI researchers and an international team of collaborators studied how a warming climate may be affecting seafloor processes in Antarctica. Image: Aaron Micallef © 2026 MBARI

MBARI leads international expedition to study impacts of climate change on Antarctic seafloor

MBARI researchers and collaborators conducted the first controlled-source electromagnetic surveys in Antarctica to understand how a rapidly warming polar environment impacts groundwater systems under the seafloor.

Why It Matters

Climate change is driving rapid warming in the Western Antarctic Peninsula. MBARI research and technology are helping reveal how this warming may be affecting geological processes, groundwater systems, and seafloor ecosystems in this remote region.

MBARI scientists recently returned home from a seven-day expedition where they conducted the first controlled-source electromagnetic survey in Antarctic waters. Funded by the Polar Research Infrastructure Network (POLARIN), the FLAIR expedition—fluid-seafloor interactions across the Antarctic seafloor under climate-driven change—was carried out in collaboration with GEOMAR Helmholtz Centre for Ocean Research Kiel, Stockholm University, The University Centre in Svalbard, the University of Barcelona, the University of Haifa, and the University of Milano-Bicocca.

The goal of the expedition was to explore how fluid flow systems under the seafloor are impacted by a rapidly warming polar environment. Working aboard the Spanish polar research vessel Hespérides, the team focused on the Bransfield Basin in the northern Western Antarctic Peninsula, a region that is experiencing some of the fastest warming in the Southern Hemisphere.

A massive bluish-white glacier towers above the ocean. To the left of the frame is a large brown rocky cliff. In the foreground is greenish-blue ocean.
The Western Antarctic Peninsula is experiencing rapid warming due to climate change, but geologists have many unanswered questions about how melting ice affects seafloor processes and ecosystems. Image: Aaron Micallef © 2026 MBARI

Beneath Antarctica’s seafloor, groundwater and gas move through what is essentially an underground plumbing system. As these fluids move around, they may sculpt the seafloor and sub-seafloor, creating conditions that can support various kinds of marine life,” said MBARI Senior Scientist Aaron Micallef, who led the expedition. “These systems are incredibly important, but their processes remain poorly understood in much of the Southern Ocean.”

The research team conducted high-resolution mapping of the seafloor, sub-seafloor, and water column, collected water and sediment samples, deployed a marine controlled-source electromagnetic (CSEM) system, and surveyed seafloor communities with a remotely operated vehicle (ROV). These tools provided a comprehensive picture of seafloor geology and ecosystems to help researchers better understand how fluids move through the Antarctic seafloor and how past ice dynamics and ongoing climate change may influence that movement. 

“It will take months to fully interpret what we mapped and sampled here, but it is already clear that these seafloor systems hold critical clues about marine hydrogeology, deep-sea ecosystems, and the stability of Antarctic seafloor in a warming world,” said Micallef.

The expedition faced many challenges due to the cold, unstable weather found in the Antarctic, but was able to conduct research in three locations: Deception Island, King George Island, and the Astrolabe Trough.

Deception Island: Severe weather leads to an unplanned, but valuable, stop

A community of invertebrates thrives on the Antarctic seafloor. Globular brown gelatinous sea squirts fill most of the frame, with several spiky yellow sponges, branched orange sponges, pink sea urchins, and orange sea stars. The background is brown muddy seafloor.
During the FLAIR expedition, MBARI researchers deployed a portable ROV to collect water samples and document life on the Antarctic seafloor, including stunning communities of sponges and tunicates. Image: © 2026 MBARI

During the first few days of the expedition, the team faced severe weather in Bransfield Strait, forcing them to adapt their schedule and conduct research at Deception Island, an active volcanic caldera.

The scientists used a multibeam echosounder on the ship to detect several upward-rising streams of bubbles escaping from the seafloor into the water. They also conducted a series of ROV dives which found the seafloor to be full of sponges and sea squirts thriving in conditions shaped by volcanic activity.

“Sometimes the most interesting science happens when plans change,” said Micallef. “This is a very different system from the methane- and groundwater-dominated environments we were targeting, but it is a powerful reminder that heat and volcanism can be key drivers of healthy seafloor ecosystems.”

King George Island: Connecting marine life and seafloor processes

A researcher processes water samples in a lab on a research ship. The researcher has short black hair and is wearing glasses, a black jacket, and dark blue jeans. He is standing in front of a gray counter, adjusting several small clear plastic vials connected to a gray plastic cylinder by clear plastic tubing. In the background are a blue metal shelf and the white walls of the lab.
Researchers examined the porewater extracted from sediment cores collected from R/V Hespérides to look for evidence of freshwater from melted ice. Image: Aaron Micallef © 2026 MBARI

The second stop on the expedition was King George Island, where the team deployed a CSEM system. On loan from the University of Malta and upgraded by MBARI engineers, the CSEM system collects information about the electrical properties below the seafloor to detect ice, brackish water, and gas buried in submarine sediments. This technology can identify fluid pathways beneath the seafloor along a 40-kilometer (25-mile) path, helping researchers survey seafloor processes over long distances. The goal was to understand how those fluids behave, move, and are stored within the rocks and sediment on the seafloor.

The team collected sediment samples using a gravity corer deployed from R/V Hespérides. From these samples, they extracted porewater—water between sediment particles—for chemical analysis. The presence of methane and freshened groundwater will help researchers determine if the degradation of underwater permafrost or changes in terrestrial groundwater systems onshore are occurring. They also used the ROV to collect water and gas samples and document the biological community living on the seafloor.

“I’m looking forward to analyzing all the different data collected at this site, but we can already see the strong connection between the processes happening below the seafloor and Antarctic marine life,” said Micallef.

Astrolabe Trough: Navigating icebergs for high scientific payoff

Five marine operations crew members prepare a scientific instrument for deployment from a research ship. The crew are wearing hard hats and insulated jumpsuits. Some are standing, and some are kneeling on the ship deck while adjusting wires. In the foreground are a bright orange float and the green metal deck of the ship. In the background are various pieces of maritime equipment with gray-blue ocean, ice-covered mountains, and overcast gray sky on the horizon.
Different types of sediments respond distinctively to electrical signals. Trailed behind a research ship, CSEM uses electromagnetic signals to detect ice, groundwater, and gas in the seafloor below. Image: Aaron Micallef © 2026 MBARI

The expedition’s final stop was the little-studied Astrolabe Trough and the adjacent continental shelf along the Western Antarctic Peninsula. The few studies that have been conducted in this region reported the presence of “mega pockmarks,” large depressions on the seafloor.

The research team deployed the CSEM system in this area as well, looking to map underground fluids and reconstruct how the repeated advance and retreat of glacier ice sheets have shaped the seafloor.

“It was exciting—and challenging—to use this technology for the first time in Antarctic waters. To conduct the survey, our team had to manage the long geophysical lines behind the boat while continuously navigating around icebergs. It’s the combination of challenging logistics and high scientific payoff that makes this region so compelling,” said Micallef.

Next steps

A polar research ship sails in waters around Antarctica. The ship has a bright reddish-orange hull and is moving away from the camera. In the foreground is grayish-blue ocean with several small drifting pieces of white ice. In the background are a large white glacier, mountains covered in white ice and snow, and overcast gray sky.
Collaborations around the world extend the reach of MBARI’s science and technology. With our peers, we are working to advance research in remote polar environments. Image courtesy of Nil Rodes/The University Centre in Svalbard

The FLAIR expedition collected the first integrated geophysical, geochemical, and biological dataset for the seafloor adjacent to the Western Antarctic Peninsula. MBARI researchers and their collaborators will now begin to analyze this trove of data to gain new insights into the role of subsurface fluids in shaping the Antarctic continental margin. Their findings will help establish a critical baseline for assessing how continued climate warming may influence hydrogeology, sediment stability, and benthic habitats in polar shelf environments.

From the Arctic to the Southern Ocean, MBARI research and technology are helping answer fundamental questions about polar environments. This information can help resource managers and policymakers make decisions about the future of these important ecosystems.

The FLAIR Expedition was made possible by POLARIN (Grant Agreement ID: 101130949), funded by the European Union’s Horizon Europe programme, with additional support from UTM-CSIC, King Sejong Station, and QPS. Additional funding for this research came from the David and Lucile Packard Foundation, as part of its longstanding support for MBARI’s work to advance marine science and engineering to understand our changing ocean.


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