Is it a fish? Is it a sea monster? Is it Cthulhu?
In 1997, while using underwater microphones to monitor volcanic activity in the depths of the southern Pacific Ocean, researchers with NOAA’s Pacific Marine Environmental Laboratory (PMEL) recorded a mysterious sound. It was extremely loud and, well, weird. The fact that no one, including NOAA, had any idea what was making the noise fed theories like the ones above. The sound came to be called “the bloop” and remained a mystery for more than a decade.
Like everyone else on the planet, the PMEL researchers wanted to know what was behind the bloop, but so little of the ocean has been explored (less than five percent, according to NOAA) that tracking down the source of one weird sound among many was not realistic. So they did what scientists do; they carried on, continuing to record and study the sounds of seafloor volcanoes and earthquakes.
From 2005 to 2010, the PMEL researchers took their acoustic survey to the area around the Drake Passage, between the tip of South America and the South Shetland Islands of Antarctica, and to the Bransfield Strait, between the South Shetlands and the Antarctic Peninsula. And there they found the source of the bloop.
It was an icequake. The sound that had intrigued so many people and spawned so many strange theories was a sound not all that uncommon in the seas surrounding Antarctica. It was the sound of an iceberg breaking apart, a phenomenon known as calving.
Read More: Meet the Doomsday Fish that Strikes Fear in the Hearts of Sailors
Antarctica’s Role in the Bloop
One wonderful thing about all the attention given to the bloop is that it was a reminder that Antarctica is down there. For those of us who live north of the equator, the southernmost continent is easy to forget.
But it would not be wise to do so.
Antarctica plays an important role in Earth’s climate. All that Antarctic ice reflects solar radiation away from Earth, helping regulate the planet’s heat balance. When the ice melts, Earth is able to absorb more solar radiation, and that can exacerbate global warming.
Though the frozen continent is warming — on average slightly faster than the rest of the planet — Antarctica’s glaciers and ice shelves have been largely stable. In fact, up until the mid-2010s, the extent of Antarctic ice was increasing, if only slightly. Then, after a peak in 2014, the yearly average of ice extent began to decline rapidly.
By 2018, a 35-year gain in ice had been wiped out in just four years. The years 2023 and 2024 set two consecutive records for low maximum ice extent in Antarctica.
Scientists aren’t sure what accounts for this change. It’s likely due in part to warmer air and ocean temperatures, but Antarctic ice mass is known to take big swings, increasing and decreasing over relatively short periods. Global warming will eventually start to melt the frozen continent, but it’s too early to know if this is the beginning of that process or if Antarctic ice will remain more or less stable for a while yet. Regardless, it’s important to figure it out.
Read More: Did an Ancient Civilization Ever Live in Antarctica?
Understanding Antarctica
Understanding what’s happening in Antarctica could help us understand what to expect for the planet as a whole in the coming years. T. J. Fudge is a climatologist at the University of Washington in Seattle. He’s currently working on a project in Antarctica that gathers data on atmospheric gases from millions of years ago to help understand how the climate responds to high levels of carbon dioxide. This will help scientists better understand the climate’s feedback mechanisms as well as help make more accurate climate models.
“Antarctica,” Fudge says, “has been on the whole a bit slow to respond to climate warming.” The continent is definitely experiencing overall warming and other changes that are leading to a rise in sea levels, he says. And those changes are expected to continue and accelerate. But the impact to the rest of the world depends a lot on the rate at which that happens.
“Some of these big glaciers are going to release meters of sea level rise, but it’s going to be over hundreds if not thousands of years,” Fudge explains. “If we can limit the impact to Antarctica so that it slows from hundreds to thousands of years, that has a giant impact for society.”
As we blow past climate benchmarks, Fudge warns that we should not get fixated on the numbers. What we should fixate on, he says, is slowing the rate of warming. And it’s not too late to do that.
Article Sources
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Avery Hurt is a freelance science journalist. In addition to writing for Discover, she writes regularly for a variety of outlets, both print and online, including National Geographic, Science News Explores, Medscape, and WebMD. She’s the author of Bullet With Your Name on It: What You Will Probably Die From and What You Can Do About It, Clerisy Press 2007, as well as several books for young readers. Avery got her start in journalism while attending university, writing for the school newspaper and editing the student non-fiction magazine. Though she writes about all areas of science, she is particularly interested in neuroscience, the science of consciousness, and AI–interests she developed while earning a degree in philosophy.
