Home Glaciers Ancient bubbles trapped in ice for thousands of years could reveal how quickly glaciers are melting

Ancient bubbles trapped in ice for thousands of years could reveal how quickly glaciers are melting


SAN DIEGO- Bubbles trapped in ice for thousands of years could sound the rise of climate change on Earth, according to new research. Scientists listen to ancient air to estimate the rate at which glaciers are melting and the impact on rising seas.

Previous studies show that warming oceans could be catastrophic for the planet. This is especially the case if global temperatures only rise by 2 degrees Celsius, scientists say. This latest research may provide more insight into these predictions.

“Recording underwater sounds will open the door to long-term acoustic monitoring of ice loss and its link to water temperature,” says study co-author Dr Grant. Deane, Scripps Institute of Oceanography, in an article. declaration.

Today, about 10% of the Earth’s land area is covered in glacial ice. Nearly 90% is in Antarctica and the rest in the Greenland Ice Sheet. If emissions continue to rise, the current rate of melting is expected to double by the end of the century.

Alarmingly, if all of Greenland’s ice melted, it would raise global sea levels by 20 feet. Ice acts as a protective blanket over the Earth and our oceans. Bright white dots keep the planet cooler.

The Arctic remains colder than the equator because more of the sun’s heat is reflected off the ice, back into space. As temperatures rise, tidal glaciers retreat, releasing pressurized bubbles.

The study identifies “acoustically distinct” underwater sounds from air trapped by ice beneath the glacier’s surface. It becomes a mixture of compressed bubble ice that creates pressure during the long passage to the end or terminus of a glacier. The ice contains air bubbles that were frozen in time before the pyramids were built. They can reach up to 20 atmospheres of pressure and generate detectable sounds when released as the ice melts.

“We observed that the intensity of sound generated by a melting terminus tends to increase as water temperature increases,” Deane reports. “That makes sense, because we expect the terminus to melt faster in warmer water, releasing bubbles into the ocean faster and generating more sound.”

The international team found that as the recording array moved away from the glacier, the variation in acoustic melting did not follow a uniform trend. Moreover, the acoustic intensities of different glaciers clustered at different levels.

This indicates that glacier-ocean interface geometry, temperature, salt and floating ice affected the measurements. The experiments will make it possible to monitor of the impact of climate change on glaciers.

“The ultimate goal is to establish long-term recording stations for underwater sound around glaciers such as those in Greenland and Svalbard, to monitor their stability over time,” says Deane.

Svalbard, a land of ice and polar bears between Norway and the North Pole, is home to some of the northernmost glaciers on Earth. They bury most of the surface of the archipelago under 200 meters of thick ice.

Glaciers can range from ice that is hundreds to thousands of years old. They provide a scientific record of how the climate has changed over time and shed light on how the planet is rapidly warming. When glaciers melt, because this water is stored on land, the runoff dramatically increases the amount in the ocean, contributing to global sea level rise.

Since the early 1900s, many glaciers around the world have been rapidly melting due to human activities, calving into the sea. Even if we drastically reduce emissions over the next few decades, more than a third of the world’s remaining glaciers will melt by the end of the century.

The study was presented at a meeting in San Diego on Acoustic Society of America.

Southwest News Service Mark Waghorn contributed to this report.