Antarctic seals with special instruments mounted on their heads are helping scientists learn more about very important glaciers. Until now, scientists have known little about how glacial meltwater is affecting the rate of change.
Seven southern elephant seals and seven Weddell seals were captured and tagged with CTD-Satellite Relayed Data Loggers around the Amundsen Sea in February 2014. Researchers collected data from the devices for one year near the Pine Island Glacier. Today, they have published their results in the journal Communications: Earth and Environment.
The Pine Island Glacier in West Antarctica has been called the “canary in the mine” for climate change. The ice is retreating so fast it’s also been called a “Doomsday Glacier,” with the potential to destabilize the entire West Antarctic Ice Sheet.
If the West Antarctic Ice Sheet melts, it will cause up to ten feet in global sea-level rise, according to EcoWatch. A new study using 25 years of satellite records has shown that ice flows in Antarctica sped up by as much as 59% faster than two decades ago. So much for moving at a “glacial pace.”
According to Gizmodo, “ice shelves collapsing in the region behave somewhat like corks popping out of a bottle of wine, releasing a torrent of ice into the sea and creating more instability and melt in the region.”
Antarctic Seals Wearing Sensors
Now, another study made possible thanks to the seals is revealing things are changing faster than expected. The seals can swim down under the ice where humans can’t reach. As they swim, sensors on the head-mounted device monitor water temperature, salinity, and pressure.
Lead author Yixi Zheng from the University of East Anglia commends the seals for their amazing contributions to the study.
“The seals, they are so amazing,” Zheng said. “They’re super good at finding small holes in the sea ice. Sometimes I feel like we should give them PhDs. They’re doing better than many scientists.”
The CTD sensors tend to work for a few months to a year and eventually fall off when the animals have their annual molt. Generally, a seal that is tagged will only do it once in its lifetime.
Fortunately, the seals tended to stay near the glaciers being studied as if on a “winter holiday.” Notably, that was most likely due to one of the key findings from the study. As the sea ice melted, it warmed the sea’s surface, causing algae and marine planktons to grow. In return, the algae fed animals, including animals that became food for seals.
Unfortunately, warming meltwaters seem to be opening up more holes near the glacier. As warmer patches form, they stir up nutrients resulting in an algae bloom. Then, ice doesn’t form over the hole again. Consequently, this process contributed to make the Pine Island Glacier one of the fastest-retreating glaciers in Antarctica.
Giant Holes in the Ice
A few years ago, seals with sensors on their heads helped scientists study a giant sea ice hole in Antarctica. The 4,000 square-mile hole is called a polynya. In this case, it was twice the size of Rhode Island.
Thanks to data from the seals, thousands of robotic floats, and satellites, the scientists determined a possible reason why the polynya stayed open. A large-scale climate pattern called the Southern Annual Mode changed wind patterns in the area. As the wind patterns changed, it stirred up the ocean, causing warm waters to rise and melt the ice.
“Observations show that the recent polynyas opened from a combination of factors – one being the unusual ocean conditions, and the other being a series of very intense storms that swirled over the Weddell Sea with almost hurricane-force winds,” said” lead author Ethan Campbell.
Now, thanks to these antarctic seals, we know that polynyas are more likely to remain open as a layer of warmer glacial meltwater forms near them.
“The volume of meltwater produced is small in comparison with the volumes of Antarctic shelf seas, but it is believed to exert a disproportionate influence on regional circulation and climate,” reported the University of East Anglia.
Antarctic seals have also helped scientists study climate change in other parts of the world, including Greenland.
Below, see how seals helped scientists track climate change from AJ+:
Featured image: Screenshot via YouTube/CNN