Collaborative Research: EAGER: GASHES: Getz Antarctic Submarine Hydrothermal Vents Exploratory Study

Antarctica contains the largest reservoir of glacial ice on the planet - enough to raise sea level by 58 meters or almost 200 feet. While the interior of the continent is uninhabited, its coastline is teeming with life. Aquatic plants support a vibrant ecosystem, which includes large seabirds like albatross, Elephant and Weddell seals, as well as orcas, and penguins. Both the glacier ice and the ecosystem may be affected by volcanic activity beneath the Antarctic continent, and this project seeks to improve our knowledge of volcanism in one part of Antarctica, the Amundsen Sea. Volcanic heat can influence the way glacier ice is distributed and how quickly it can flow from land to sea. In addition, undersea or under-ice volcanoes provide important nutrients to feed ocean plankton and other organisms at the base of the food chain. This project will explore evidence for undersea volcanism in the Amundsen Sea. Gases such as helium, dissolved in seawater, will be tested for evidence that volcanic activity is present in the Amundsen Sea. If this evidence can be established, the project will seek to evaluate where the volcanism is located and how volcanic fluid leaks into the ocean, including into the part of the ocean that receives sunlight for growth. This project seeks further evidence of submarine or subglacial and syn-glacial rift features, perhaps connected to the greater West Antarctic Rift System. Helium isotopes are a sensitive diagnostic tracer of hydrothermal plume pathways into the ocean column. Noble gases provide high-fidelity tracing of ice and atmospheric processes in the ocean. Together, they can trace the pathways of hydrothermal fluid and reveal any relationship between glacially-derived freshwater and hydrothermal plumes. This project will measure and interpret discrete water samples collected during a research vessel expedition to the Amundsen Sea that took place between January and March 2022. The project will measure the five stable noble gases (Helium, Neon, Argon, Krypton, Xenon) and helium isotopes dissolved in seawater surrounding a submarine geologic feature at the front of the Getz Ice Shelf, and in adjacent coastal waters. The project will look for prior for evidence of hydrothermal fluid in the Amundsen Sea, evaluate whether mantle material is presently being released, explore the evidence that iron in hydrothermal fluid is being mixed into the water column, and determine how meltwater inputs to the Antarctic Coastal Current evolve along major Amundsen ice shelves. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.