2024-09-03 09:05:30
Engineers who specialize in building NASA spacecraft are designing a fleet of robotic underwater probes to measure how fast climate change is melting the vast ice sheets around Antarctica and what that means for sea level rise, BTA reports. Reuters.
The prototype submersibles, developed by NASA’s Jet Propulsion Laboratory (JPL), were tested during a US Navy field camp in the Arctic, being lowered under the frozen Beaufort Sea north of Alaska in March.
“These robots are a platform for carrying scientific instruments to the most inaccessible places on Earth,” explained Paul Glick, a robotics engineer at JPL and the IceNode project scientist, in a report published Thursday on the website of NASA.
The purpose of the probes is to provide more accurate data on the rate at which warming ocean waters around Antarctica are melting the continent’s coastal ice, which will allow scientists to improve computer models for predicting future sea-level rise.
The fate of the world’s largest ice sheet is the focus of nearly 1,500 scientists and researchers who gathered this week in southern Chile for the 11th conference of the Scientific Committee for Antarctic Research.
A JPL analysis published in 2022 found that the thinning and breakup of Antarctica’s ice shelf has reduced its mass by about 12 trillion tons since 1997, double previous estimates.
According to NASA, if it were to melt completely, the loss of the continent’s ice shelf would raise global ocean levels by approximately 60 meters.
Ice shelves are floating slabs of frozen freshwater that extend miles from land into the sea. They form over thousands of years and act as giant buttresses holding back glaciers that would otherwise easily slide into the surrounding ocean.
Satellite images show that the breaking off of parts of the glaciers in the form of icebergs is happening at a faster rate than nature can replenish the growth of the shelf.
At the same time, rising ocean temperatures are eroding the shelves below, a phenomenon scientists hope to study with greater precision using the Ice Node underwater probes.
The cylindrical devices, about 2.4 m long and 25 cm in diameter, will be launched through boreholes in the ice or from vessels in the sea.
Although unpowered, the robotic probes will drift along the currents, using special software guidance to reach the “work zones” where the frozen freshwater shelf meets the salt water of the ocean or land. An additional difficulty is that these zones are unavailable for satellite signal.
“Our goal is to get data directly from the melting zone between the ice and the ocean,” says JPL climatologist Ian Fenty.
Upon arrival at the work zones, the submersibles will drop their ballast and rise up to attach to the underside of the ice shelf using three-pronged spikes that pop out of the hull.
The probes will then continuously record data from the ice for a year, including seasonal fluctuations, before being released to return to the open sea and transmit the readings via satellite.
Until now, the thinning of the ice shelf was documented by satellite altimeters that measured the changing height of the ice above.
During the field test in March, a prototype probe descended 100 meters into the ocean to collect data on salinity, temperature and currents. Previous tests were conducted in California’s Monterey Bay and beneath the winter-frozen surface of Lake Superior off Michigan.
Ultimately, scientists think 10 probes would be ideal for collecting data from a single cavity on an ice shelf, but “we still have a lot of development and testing to do” before a full-scale probe deployment schedule is set, Glick said.