I think it is always important to listen to scientists, as they are specialists in their field of research and know it best. So in August, I had the chance to accompany glaciologist Lindsey Nicholson on a field trip to Hintereisferner to collect data and do field work. Hintereisferner is a typical alpine valley glacier with a long, pronounced tongue.

The format of this blog post is a little bit different this time. Most of the infos are in the captions of the images. So take your time and read it all. :)

View over the tongue of Hintereisferner towards the valley. The glacier is one of the biggest in Tyrol.

A glacier as a laboratory

Research at the Hintereisferner has a long history. Since over 100 years, glaciologist have observed and analysed the ice giant. That is why it has been classified as one of the key “reference glaciers’” by the World Glacier Monitoring Service. The main focus is on measuring the mass balance of the glacier each year. Scientists of the University of Innsbruck measure the melting of ice, called ablation, during the summer months and the addition of snow on the ice, called accumulation, during the winter. In addition, Hintereisferner is also serving as an Open Air Laboratory.

Meet Lindsey Nicholson

Lindsey has a Ph.D. in Glaciology, is Assistant Professor at the Department of Atmospheric and Cryospheric Sciences (ACINN) at the University of Innsbruck, is a co-founder of Girls on Ice, has worked on glaciers all around the world and has published several academic papers. Together with her colleague Rainer Prinz, she is responsible for the data collection for the mass balance of Hintereisferner.

About half way to Hintereisferner. About 100 years ago this valley was still filled with ice, as Lindsey explains to us.

It's a long way to the glacier, but we can finally see the ice in the distance. In case you are wondering: The wooden sticks are used for the ablation stakes to measure the melting.

In 1979 the glacier ended here, today the end is in the far distance.

We are on the glacier, even though it does not look like it. Beneath the layer of rocks is ice. The first several hundred meters of the Hintereisferner's tongue are covered with this debris.

We reached the uncovered ice. Now it's only ice beneath our feet for a few kilometres.

An ablation stake. One stick is two meters long. 5 sticks are connected together and placed in a 10 meter deep hole in the ice. Two sticks have melted out, thus the glacier lost 4 meters of thickness at this location. In November, Lindsey told me that at the last data collection in September 2024, the stick had melted out further, resulting in a **total loss of ice thickness of 5.5 metres in just one year**.
The loss of ice varies, depending on where you are on the glacier. Of course the ice in lower elevations melts faster. But also the ice close to the mountain slopes on each side of the glacier melts faster.

Lindsey measures how much of an ablation stake has melted out of the ice. By the way, **during a hot summer day, between 10 to 20 cm of ice can melt.**

All measurements are written down. Every stake has an identification number.

After a successful first day on the glacier, we hiked up to a small hut, which the University of Innsbruck had installed for the scientists at over 3.000 meters above sea level. It is a basic shelter with no running water and no electricity, however the views over the Hintereisferner are incredible.

The next day started earlier. Sunrise over Hintereisferner.

Heading back down to the glacier to redrill ablation stakes and collect data.

Out of balance?

At this point, you might ask yourself, what the heck is a mass balance? Simply put, it is the difference between the ice gained during winter and the ice lost in summer. So a negative mass balance means that the glacier is losing ice and is receding. The ACINN calculates the mass balance for the Hintereisferner every year based on the data collected. Since 1985 the glacier had only negative mass balances. The year 2022/23 was the third worst since the start of measuring in 1953. It is clear that the glacier is clearly not doing well and is melting away more and more. I won’t bother you with more scientific terms or numbers, but if you are interested in that, have a look at the website of ACINN. The complete report for this year (2023/24) should be available soon. The total mass balance of 2023/24 was -1100 kg/m2. This corresponds to a loss of glacier ice equal to a 110 cm thick layer of water on the entire glacier surface. According to glaciologist Rainer Prinz the Glacier Loss Day 2024 of Hintereisferner was around 10th August 2024. The Glacier Loss Day marks the day a glacier has lost all the mass gained during the previous winter and from now on melts constantly. It serves as an indicator of a glacier’s health and is comparable to the Earth Overshoot Day.