Ancient underwater mountain range discovered in Southern Ocean
Ancient underwater mountain range discovered in Southern Ocean
Scientists have discovered an ancient underwater mountain range hidden within the world’s strongest ocean current, the Antarctic Circumpolar Current.
This revelation came to light during a high-resolution mapping expedition conducted by an Australian and international research team.
The research voyage, aboard the CSIRO research vessel Investigator, explored a vast area of the Southern Ocean, stretching 20,000 square kilometers between Tasmania and Antarctica. The seafloor, reaching depths of 4,000 meters, was mapped in unprecedented three-dimensional detail, revealing a spectacular chain of eight long-dormant volcanoes, with peaks soaring up to 1,500 meters high.
Four of them are new discoveries, and we filled in details on two seamounts and a fault line ridge partially mapped on a previous voyage.
Dr. Chris Yule, a geophysicist with CSIRO, expressed excitement over the findings, which included four newly discovered volcanoes and detailed information on previously partially mapped seamounts and a fault line ridge. The survey area, located 200 nautical miles west of Macquarie Island, sits atop the tectonically active Macquarie Ridge, where these seamounts were formed by hotspot magmatism within the last 20 million years.
The FOCUS voyage was designed to complement the capabilities of the new Surface Water and Ocean Topography (SWOT) satellite, developed jointly by NASA and the French space agency CNES. This collaboration allowed for simultaneous mapping from both space and sea, providing a comprehensive view of the ocean’s fine-scale features.
Dr. Benoit Legresy, the voyage’s chief scientist, emphasized the urgency of understanding the ocean’s role as a ‘climate shock absorber,’ absorbing over 90% of the heat from global warming and about 25% of human CO2 emissions. The team focused on how heat is channeled towards Antarctica, affecting ice melt and contributing to sea-level rise — a critical concern for climate change mitigation efforts.
Dr. Helen Phillips, co-chief scientist from the University of Tasmania, highlighted the importance of the seafloor’s topography in influencing ocean dynamics. She explained that the Antarctic Circumpolar Current interacts with the seafloor, creating eddies that play a significant role in transporting heat and carbon deeper into the ocean, thus serving as a buffer against global warming.
The discovery of these underwater mountains is more than just a geological wonder; it provides crucial insights into the behavior of ocean currents and their impact on climate.