Australian Research Vessel Discovers New Underwater Mountain Range
Scientists aboard the Australian research vessel RV Investigator have uncovered an underwater mountain range, advancing efforts to understand subsea currents and heat transfer across the Antarctic Circumpolar current.
CSIRO, the Australian government agency responsible for scientific research, announced that the range consists of eight dormant volcanoes reaching heights of 1,500 meters above the seafloor. They were discovered halfway between Tasmania and Antarctica, and four of the volcanoes are new discoveries.
According to the team, the seamounts must have been formed by volcanoes arising from hot-spot magmatism within the last 20 million years. The new discoveries were made possible through high-resolution mapping with Investigator’s multibeam echosounder system. The research vessel was able to survey down through layers of swirling currents to the seafloor 4,000 meters below.
“To our delight, we’ve discovered a spectacular chain of ancient seamounts," said Chris Yule, CSIRO geophysicist. "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. We now know the ridge, just west of the survey area, drops into a valley over a 1,600-metre-high cliff."
Scientists have been working aboard the vessel in the Antarctic Circumpolar Current over the last five weeks to understand how heat leaks across the current's natural barrier. Heat transfer from warmer, lower-latitude water contributes to melting Antarctic ice shelves.
The team says that the intensive survey has been instrumental in advancing the understanding of the oceans, which absorb more than 90 percent of heat due to global warming and around 25 percent of human CO2 emissions. “We’ve been working in a gateway where heat is funneled towards Antarctica, contributing to ice melt and sea level rise. We need to understand how this gate works, how much heat gets through and how this may change in the future,” said Benoit Legresy, the voyage's chief scientist.
The team is also helping to calibrate the new Surface Water and Ocean Topography (SWOT) satellite by simultaneously mapping fine-scale ocean features with the satellite and the vessel. SWOT was jointly developed by NASA and the French space agency Centre National d’Études Spatiales (CNES). While the ship measures the properties of the ocean inside the current, the satellite measures the height of the ocean surface in an unprecedented high resolution from space.