The highest mountain on Earth, Mount Everest, has fascinated adventurers, climbers, scientists and nature lovers alike for centuries. Their 8,848 meters high above sea level attract locals and strangers and there have only been a few thousand people who have managed to reach the top of this peculiar mountain in the Himalayas.
However, one of its most mysterious characteristics remained precisely an enigma, a mystery. The mountain, once sunset occurs, wake up and burst into eerie noises surrounding the mountain peak.
Everest at night
night noises
What are these strange night noises on Everest? An international team of researchers embarked on an expedition to the Nepalese Himalayas in 2018, led by glaciologist Evgeny Podolskiy, an expert at the Arctic Research Center at Hokkaido University, to investigate the cause of these terrifying, deafening nocturnal sounds. During the week-long hike up the mountain, the team camped on an open glacier that was clear of debris and began to notice the strange noises that started at nightfall.
What have they discovered?
As the Sun sets, Everest awakens. His research has revealed that the sharp drops in temperature that take place after dark are responsible for this fan of sounds, as the interiors of the glaciers around Mount Everest break and splinter.
“It was an amazing experience because it’s a great area to work in. Basically, I have lunch looking at Everest,” Podolskiy said. And… when night came: “We heard this loud noise. We noticed that our glacier is bursting or exploding with cracks at night“, the experts explain in their study published in the journal Geophysical Research Letters.
The researchers found abrupt nocturnal temperature drops due to the high altitude of the glacier that caused the explosive cracks. The temperature could drop to around -15 degrees Celsius at night when during the day it was hot enough to wear a T-shirt. The team placed sensors in the ice to measure vibrations in the depths of the glacier, the same technology used to measure the magnitude of earthquakes. They confirmed that the strange noises were related to extreme cold when they returned to sea level and examined the seismographic data.
Their research is one of the first to show such a large amount of seismic activity due to thermal fracture within the ice. The cause? The behavior of glaciers as the effects of climate change continually warm the planet.
“Local ice turns out to be very sensitive to this high rate of change,” says Podolskiy.
We cannot ignore that the glacial ice in the Himalayas is melting at a devastating rate that endangers millions of people and the economies of South Asian countries. The rate of ice loss is currently 10 times faster than during the previous seven centuries.
The research not only contributes to our understanding of glacier behaviour, but also builds on the growing body of knowledge about the impact of climate change on these systems so important to the balance of life on earth.
Reference:
Evgeny A. Podolskiy et al. Nocturnal Thermal Fracturing of a Himalayan Debris-Covered Glacier Revealed by Ambient Seismic Noise, Geophysical Research Letters (2018). DOI: 10.1029/2018GL079653
