Scientists have discovered why Mount Everest makes terrifying noises at night

As the sun sets in the Himalayas and temperatures plummet, a cacophony of eerie noises erupts deep within the glaciers surrounding Mount Everest.

Researchers led by the glaciologist Evgeny Podolskiy have found it that the chorus of breaking and shattering sounds in the high-altitude glaciers is the result of sharp drops in temperature after dark causing ice to crack.

The team discovered the source of the noises in 2018 after more than a week of trekking through the Nepalese Himalayas to test the seismic activity of the Trakarding-Trambau glacier system there.

Dr. Podolskiy and his team spent three weeks shivering on the glacier in full view of Mount Everest, unsure of the source of the booming nighttime noises, but confirmed they were related to the extreme cold when they returned to sea level and examined seismographic data. .

Their study was one of the first to demonstrate such a large amount of seismic activity due to the thermal break in the ice, building on a huge body of research on the behavior of glaciers as the effects of climate change continue to warm the planet.

This map shows the locations of the seismic monitoring network and other instruments in the Trakarding-Trambau glacier system in Nepal

Dave Hahn, an expedition leader who has completed 15 Everest summits, spoke of hearing the bizarre noises at night when he and fellow climbers would rest, including “ice and rocks crashing down in various places in the valley.”

“It’s hard to sleep,” he added.

When Dr. Podolskiy and his team went to the Nepalese Himalayas to test the seismic activity of the Trakarding-Trambau glaciers, they landed at about three miles above sea level, in full view of Everest, which stands at about 29,000 feet. .

Dr. Podolskiy, who works at the Arctic Research Center at Hokkaido University, Japan, said: ‘It was a great experience because it is such a beautiful area to work in.

“Actually, I’m having lunch looking at Everest.”

During the day, Dr. Podolskiy and his team could work comfortably in T-shirts.

But by nightfall, the temperature can drop to about -15 degrees Celsius or 5 degrees Fahrenheit.

In the dark, he and his team heard “this loud bang,” adding, “We’ve noticed that our glacier is cracking or exploding with bursts at night.”

The team placed sensors on the ice to measure vibrations deep in the glacier, the same technology used to measure the magnitude of earthquakes.

Researchers collected the seismic data on tremors and compared them to temperature and wind data, which helped establish a firm link between the temperature swings and nighttime noise.

Dr. Podolsky and fellow researchers wrote in the journal Geophysical Research Letters, “Local ice appears to be very sensitive to this high rate of change.”

The research could help more teams of glaciologists and climate experts better understand the behavior of glaciers in remote areas, such as deep in the Himalayas, which has one of the largest ice reserves on Earth.

The glacial ice in the Himalayas is melting at a devastating rate, endangering millions of people and the economies of South Asian countries. Massive ice sheets in the region have shrunk ten times faster over the past four decades than in the previous seven centuries.

A 2021 study published in the journal Scientific Reports found that glaciers in the Himalayas have lost about 40 percent of their surface area over the past few hundred years, or about 390 to 586 cubic kilometers of ice — enough to raise global sea levels by 0.92 to 1.38 millimeters