Digging Into Icy Depths To Better Understand Glacial Melt
Holes up to 200 metres deep were drillled into the Khumbu glacier as part of the earlier investigation. Minimum temperatures were found to be minus 3.3°C, far warmer than the Everest slopes, which are minus 9 or 10°C (Image by University of Leeds Press Office)
- A research team is drilling boreholes in Mount Everest’s Western Cwm to measure glacier temperatures and understand why Himalayan glaciers are warming and melting faster than expected.
- Data from the glacier could transform predictions of glacial retreat and future water supply across the Himalayan region.
- Findings from this deep-glacier monitoring effort could improve climate modelling and glacial melt forecasts, offering critical insights during a time of rapidly retreating glaciers and global freshwater stress.
The icy silence of the Western Cwm glaciers of Mount Everest will be broken this summer by the sound of battery-operated drills for boreholes as part of a new experiment to determine why glaciers are losing their cool. A team of researchers, including an Indian glaciologist, plans to push the frontiers of glacier science by getting to the core of the matter by spending a few weeks in the Western Cwm in April and May this year where they will continue their investigation on why the ice at one of the world’s highest glaciers is at melting point.
The world over glaciers are retreating, melting at a faster rate than ever before but there is inadequate information to make accurate predictions and reasons for increased melt. Losing their Cool: are high-elevation heat exchanges warming Himalayan glaciers?, is a three-year project by academics from the University of Leeds, Aberystwyth University, University of Bergen (Norway) and Uppsala University (Sweden), funded by the Natural Environmental Research Council (NERC) UK, which aims to investigate the physical interactions between the atmosphere and the glacier surface at high-elevations on Khumbu Glacier in Nepal.
Duncan Quincey, the expedition leader and a professor from the School of Geography, University of Leeds, in an interview for this article, said that ice temperatures in the Khumbu Glacier are surprisingly warm. This is based on findings from an earlier investigation, which drilled into the ice below Everest Base Camp. “We think the sun is so strong at those high elevations and even at air temperatures of minus five to 15°C, it can still melt the glacier surface. We are going to observe this for the first time and the way we can observe this is to drill holes and put a video camera which has a 360-degree view which can see all the way down. We can see what the structure of the surrounding snow and ice is, and we can see if the meltwater has gone into the snow and ice and if it has frozen again,” said Quincey.
The earlier research from 2016-19 found that ice temperatures in Khumbu Glacier, the world’s highest debris-covered glacier, were warmer than expected. It involved drilling holes for 200 metres and the study indicated that the minimum temperature was minus 3.3°C, which prompted a concern. Given the annual average temperatures at Camps 1 and 2 on the Everest slopes are around minus 9 or 10°C, the ice temperatures at Khumbu were expected to be similar.
The current working hypothesis is that strong solar radiation in the Western Cwm is sufficient to warm the ice by several degrees, at the point of formation.
So in this round of study, the team plan to place the sensors at a shallower depth of 15 metres. “We are hoping to be able to show that when the sun is heating the glacier, the meltwater percolates into the snow and refreezes and that’s what heats the snow and ice,” said Quincey.
If the researchers can show that this effect is real, it means, said Quincey, that at the moment researchers are not really modelling forward in the correct way. “We are making projections that tell people, aid agencies, governments how long these glaciers are going to survive but we don’t account for this process (melting and refreezing). If the glaciers are warmer than we have been able to understand previously, they will melt faster than currently predicted. So we need to take our observations and incorporate them into future simulations which can indicate how long these glaciers will survive.”
Further, the seasonal melt water which downstream communities rely on may not last for as long as it was previously estimated. This foretells “a period of extreme climate crisis in terms of shortages and extreme events which will be in the nearer future than we’ve previously realised,” Quincey pointed out.
The processes at high elevations define the glacier characteristics all the way down. “If this ice is warmer than we imagined, it will explain the recession rates of these glaciers which are melting at a rate which is beyond historic precedence,” he said. “That’s likely because the ice is at a warmer temperature than we have accounted for. This has knock-on consequences for those who rely on the meltwater that comes from these glaciers, but also in terms of the formation of the glacial lakes which is affecting the whole of the Himalayan region.”
As part of this project, the 15-metre-deep boreholes will be drilled at elevations of 6,000-6,500 metres above mean sea level and sensors will be placed within them to record the ice temperatures for a year.
There are plenty of unknowns in this research as only a handful of scientists have been up to the Western Cwm for research and not for drilling boreholes or for a long-term study.
Glaciers may be melting faster than predicted
Changes in the rate of glaciers thawing would threaten water supply in the Himalayan region and this research has the potential to make more accurate models and predictions since it is based on real-time data. “This data can give an idea of glacial melt and rising temperatures and we can make predictions for 2030 or 2050 and so on, until the end of the century, and beyond, relating to how long these glaciers will survive, which is highly relevant for all the countries of the Himalayan arc. It can help make more accurate predictions of glacial retreat and warming in that region,” Quincey pointed out.
Co-investigator Bryn Hubbard, a professor at the Aberystwyth University’s Department of Geography and Earth Sciences, said, “It may surprise many that snow could be melting at sub-freezing air temperatures high up within Everest’s Western Cwm, but the possibility needs to be investigated and measured. These temperature measurements will improve computer models that are used to predict future changes in glacier extent and water supply – particularly important in this heavily-populated and water-stressed region.”
The project builds on Aberystwyth University’s expertise in borehole drilling and sensor development to record ice temperatures deeper into the ice and at higher elevations than ever before attempted. “Satellites will send real-time data back from the Western Cwm directly to our computers in the UK, reducing the number of future trips required to download and service the equipment,” he said in a press statement.
High altitude challenges
This research is especially relevant in the light of the United Nations World Water Development Report 2025, which states that glaciers in the Hindu Kush Himalaya mountain ranges were disappearing at an alarming rate – 65 percent faster in 2011-2020 than in the previous decade and melting faster than the global average. The eight-member team will be in the Western Cwm for about two weeks and in that area for six weeks at a height of 6,000 to 6,400 metres.
Ann Rowan, a professor from the University of Bergen said this is the first attempt to measure deep glacial temperatures in the accumulation zone of a Himalayan glacier, at over 6000 m elevation. In an email interview, she said, “These results will tell us how sensitive these glaciers are to climate change and if the effects of rapid recent warming extend to the highest elevations in the Himalaya.” As a glacial geomorphologist, in this project, Rowan will be building ice flow models that can be used to understand the glacier temperature measurements. Combining field data with models is difficult and she said, “To make this work, we consider how to do so from the start of the project so that we can collect data at the right scales to do so.”
One of the main challenges at the research site is the altitude – it takes time for some researchers to acclimatise and then it’s still slow to move around and work above 5000 m. Additionally, there is a large variation in temperatures which can change from 20°C in the daytime to -10 °C at night.
In addition to the temperature and altitude, Quincey said the main challenges relate to the equipment to drill the holes, and “running power-hungry drills, logistics and the physical aspects of staying at such a high elevation. We need batteries to power the drills and they don’t like cold, so power is a challenge and it is possible that drills might get stuck within the bore holes which tends to happen in the ice and at times you have to abandon them.” There is also the logistics of moving the heavy equipment, some of it by helicopter, and the considerable physical challenges. Other than negotiating the dangerously unstable Khumbu Icefall, the team will deal with low oxygen levels and extreme temperatures ranging from above 0 to 5°C to below minus 15 °C. “Our bodies will be under a lot of stress and there could be potential issues with altitude sickness and extreme temperatures which fluctuate between a warm strong sun in the day and cold nights, which means our bodies work overtime to keep warm,” he added.
The Indian glaciologist on the team, Sunil Oulkar, a postdoctoral research fellow and Quincey’s colleague at the School of Geography, has spent eight years and over 600 days studying glaciers in the Lahaul Spiti region in Himachal Pradesh for his Ph.D. He is looking forward to using his expertise to study surface temperatures of glaciers and is excited about his first trip to the Everest Base Camp. Oulkar said he will be contributing to the project by focusing on glacier energy balance coupled with firn (snow that is a year old and has not yet transformed to glacier ice) modelling studies. “My role involves analysing subsurface heat exchanges to understand ice temperature variations and the role of melting and refreezing in high-altitude glaciers under a warming climate. We will be installing weather stations to collect key meteorological data for energy balance studies,” he said.
This research takes place in this UN International Year of Glaciers’ Preservation and the UN Decade of Action 2025-2034 for the Cryospheric Sciences and is critical as mountains provide up to 60% of the world’s annual freshwater flows, according to the UN World Water Report 2025. The report pointed out that glaciers across the world are melting at unprecedented rates, and mountain waters are often the first to be exposed – and the most vulnerable – to the severe consequences of climate and biodiversity disruptions, putting at risk two billion people who depend on meltwater.
(Published under Creative Commons from Mongabay India. Read the original article here)
