Scientists explore a seafloor area newly exposed by iceberg A-84; discover vibrant communities of ancient sponges and corals.
Video and photos available here.
PUNTA ARENAS, Chile— An international team on board Schmidt Ocean Institute’s R/V Falkor (too) working in the Bellingshausen Sea rapidly pivoted their research plans to study an area that was, until last month, covered by ice. On January 13, 2025, an iceberg the size of Chicago, named A-84, broke away from the George VI Ice Shelf, one of the massive floating glaciers attached to the Antarctic Peninsula ice sheet. The team reached the newly exposed seafloor on January 25 and became the first to investigate an area that had never before been accessible to humans.
The expedition was the first detailed, comprehensive, and interdisciplinary study of the geology, physical oceanography, and biology beneath such a large area once covered by a floating ice shelf. The ice that calved was approximately 510 square kilometers (209 square miles), revealing an equivalent area of seafloor.
“We seized upon the moment, changed our expedition plan, and went for it so we could look at what was happening in the depths below,” said expedition co-chief scientist Dr. Patricia Esquete of the Centre for Environmental and Marine Studies (CESAM) and the Department of Biology (DBio) at the University of Aveiro, Portugal. “We didn’t expect to find such a beautiful, thriving ecosystem. Based on the size of the animals, the communities we observed have been there for decades, maybe even hundreds of years.”
Using Schmidt Ocean Institute’s remotely operated vehicle, ROV SuBastian, the team observed the deep seafloor for eight days and found flourishing ecosystems at depths as great as 1300 meters. Their observations include large corals and sponges supporting an array of animal life, including icefish, giant sea spiders, and octopus. The discovery offers new insights into how ecosystems function beneath floating sections of the Antarctic ice sheet.
Little is known about what dwells beneath Antarctica’s floating ice shelves. In 2021, British Antarctic Survey researchers first reported signs of bottom-dwelling life beneath the Filchner-Ronne ice shelf in the Southern Weddell Sea. The expedition on Falkor (too) was the first to use an ROV to explore sweeping landscapes containing abundant life in this remote environment.
The team was surprised by the significant biomass and biodiversity of the ecosystems and suspect they have discovered several new species.
Deep-sea ecosystems typically rely on nutrients from the surface slowly raining down to the seafloor. However, these Antarctic ecosystems have been covered by 150-meter-thick (almost 500 feet) ice for centuries, completely cut off from surface nutrients. Ocean currents also move nutrients, and the team hypothesizes that currents are a possible mechanism for sustaining life beneath the ice sheet. The precise mechanism fueling these ecosystems is not yet understood.
The newly exposed Antarctic seafloor also allowed the international team, with scientists from Portugal, the United Kingdom, Chile, Germany, Norway, New Zealand, and the United States, to gather critical data on the past behavior of the larger Antarctic ice sheet. The ice sheet has been shrinking and losing mass over the last few decades due to climate change.
“The ice loss from the Antarctic Ice Sheet is a major contributor to sea level rise worldwide,” said expedition co-chief scientist Sasha Montelli of University College London (UCL), United Kingdom, also a 2019 Schmidt Science Fellow. “Our work is critical for providing longer-term context of these recent changes, improving our ability to make projections of future change — projections that can inform actionable policies. We will undoubtedly make new discoveries as we continue to analyze this vital data.”
In addition to collecting biological and geological samples, the science team deployed autonomous underwater vehicles called gliders to study the impacts of glacial meltwater on the physical and chemical properties of the region. Preliminary data suggest high biological productivity and a strong meltwater flow from the George IV ice shelf.
The expedition was part of Challenger 150, a global cooperative focused on deep-sea biological research and endorsed by the Intergovernmental Oceanographic Commission of UNESCO (IOC/UNESCO) as an Ocean Decade Action.
“The science team was originally in this remote region to study the seafloor and ecosystem at the interface between ice and sea,” said Schmidt Ocean Institute Executive Director, Dr. Jyotika Virmani. “Being right there when this iceberg calved from the ice shelf presented a rare scientific opportunity. Serendipitous moments are part of the excitement of research at sea – they offer the chance to be the first to witness the untouched beauty of our world.”
About the Organizations
Schmidt Ocean Institute was established in 2009 by Eric and Wendy Schmidt to catalyze the discoveries needed to understand our ocean, sustain life, and ensure the health of our planet through the pursuit of impactful scientific research and intelligent observation, technological advancement, open sharing of information, and public engagement, all at the highest levels of international excellence. For more information, visit www.schmidtocean.org.
CESAM is a Research Unit of the University of Aveiro (UA) with the status of Laboratório Associado (Associated Laboratory) since 2005, and it has been evaluated with the highest grade of Excellent since 2014. The mission of CESAM is to promote transdisciplinary and transformative research and knowledge exchange to address pressing societal needs. This includes tackling environmental and marine challenges, understanding global change processes, and providing sustainable solutions for the management and conservation of natural resources. The center is committed to the well-being of ecosystems and humanity, building upon a One-Health approach, which emphasizes the interconnectedness of human, animal, and environmental health. CESAM achieves its goals through both fundamental and applied research. CESAM’s vision is to become an internationally recognized leader in marine and environmental sciences. The center strives for excellence in both fundamental and applied research, with a deep commitment to understanding and solving the complex marine and environmental challenges facing the world today.
UCL is a diverse global community of world-class academics, students, industry links, external partners, and alumni. Our powerful collective of individuals and institutions work together to explore new possibilities. Since 1826, we have championed independent thought by attracting and nurturing the world’s best minds. Our community of more than 50,000 students from 150 countries and over 16,000 staff pursues academic excellence, breaks boundaries and makes a positive impact on real world problems. The Times and Sunday Times University of the Year 2024, we are consistently ranked among the top 10 universities in the world and are one of only a handful of institutions rated as having the strongest academic reputation and the broadest research impact. For almost 200 years, we are proud to have opened higher education to students from a wide range of backgrounds and to change the way we create and share knowledge. Learn more at https://www.ucl.ac.uk/
