La Venta - Ice Project - Gorner and Alestch

La Venta - Ice Project - Gorner and Alestch

La Venta - Ice Project - Gorner and Alestch
La Venta is a geographical exploration association that has been working with Ferrino for decades. One of the most recent expeditions, held in October 2022, saw the glaciologists and
speleologists of La Venta and Inside The Glaciers busy surveying the Swiss glaciers of Aletsch and Gorner, in order to study the glacial masses from the inside and understand their evolution, in a constant combination of exploration and scientific research.
We tell you about the results of this expedition with this interview with Alessio Romeo, La Venta member and geologist.

Alessio, what are the main results of your expedition?
On both glaciers, Aletsch and Gorner, we noted the effects of the last hot summer, which strongly marked all the glaciers in the Alps without sparing even these two giants. Many cavities showed morphological changes due to high melting and thus an enlargement of the underground environments and, in some cases, the collapse of these structures due to the collapse of the vault.

In your reports you read a lot about contact caves. What are they and why are they important?
Contact caves are natural structures that form between rock substrate and ice. The best known, which have been explored and depicted for a few centuries, are those at the front
of glaciers from where meltwater escapes during the warmer months of the year. Then there are contact cavities created by the meeting of torrents from outside that creep under the ice due to the melting power that their waters (at a higher temperature than the melting temperature) have on the ice. These cavities in particular have recently been the subject of study by some of us because they represent, in our opinion, an important factor in the reduction of glacier mass, a phenomenon that is, moreover, rather invisible to the eyes of those who only analyse and quantify the mass balance of glaciers through satellite images ...
Quantifying, even if only approximately, the amount of ice lost over the course of a year below the surface will allow us to understand the real impact of these cavities on glaciers and the future that awaits them.



What kind of recurrent measurements do you make inside the glaciers? What are the main parameters you monitor?
Mainly temperatures of both water and air, and with constant recurrence also volumes through 3D scans and photogrammetry.
We also collaborate with some professional companies operating in the field of drones, photogrammetry and high-definition 3D surveys with laser scanners.
Among these realities are VIGEA, an Italian company founded by another La Venta partner, Tommaso Santagata, and Flyability, a Swiss company that has developed, thanks also to  he collaboration with La Venta itself, a special spherical drone capable of withstanding impacts and, above all, able to support cavers in the exploration of caves when environmental conditions would make it impossible for a human being to progress or even survive.
With the use of these cutting-edge technologies, we are able to obtain three-dimensional models of cavities in real time, which are extremely useful in the study of cavities and which have further implications, such as in the field of virtual reality, where through the use of special visors, anyone can 'visit' places that would otherwise be inaccessible.

The first surveys were made on the Alestch glacier: what did you find?
Three of us set off for the Alestch, a day late due to rain, to reach the Marjelensee contact cave where the true blue, that unique, electric blue colour of this spectacular ice cavern in the heart of the Alps awaits us.
Not since 1864 have Swiss weather stations recorded such high temperatures for the month of October as this year. An October that gave us heavy rainfall even at 2400 m a.s.l. where we had hoped for snow.
The high temperatures outside and the rainfall in fact made the torrent, which descends from the mountainside creating the cave itself, a raging river, a fact that did not please us, as we expected difficult water conditions inside the cavity.
Arriving at the entrance, we notice the substantial morphological changes compared to 2021: the collapse of the entrance portal and the considerable reduction in its size, as well as  the collapse ofthe glacier at the cave and the consequent lowering of the vault, which we can already tell from the outside.
As predicted, the water of the torrent overbearingly flows into the main gallery of the cave, ending up in a siphon lake a few dozen metres inside it, right there where we used to reach a rather narrow passage about fifteen metres below (now submerged) with the help of a rope, a passage never yet crossed (at least not by us) as it is always impassable because of the torrent that flows into it... and once again this year, to our great disappointment, we do not have the opportunity to explore further. We therefore dedicate ourselves to the topographical survey, especially of the galleries to the right of the portal, which were also present in the last two years but which have also undergone a considerable change, increasing in size and development. The entire cavity is pervaded by a cloud of humidity: water mist that sticks to the vaults of the galleries and creates dripping everywhere: this too certainly contributes to the melting process.
The next day we attempt the glacier traverse to explore the diametrically opposite side of the main tongue, where the presence of a stream suggests the existence of a cave on contact. Towards the halfway point, where the crevasses become deeper and deeper and perfectly perpendicular to our direction of progression, we decide to return.



And on the Gorner?
On the Gorner glacier, which has been lowered by several metres since 2021, we found some rather remarkable morphological changes in both the contact caves and the glacial mills.
Contact Cave 3 (CC3 below), the target contact cave of our studies, greeted us with a huge collapse of the vault in the main gallery right where we had placed one of the sensors, which we nevertheless managed to recover despite the risk of a further collapse of the ice sheets hanging over our heads.
Analysing the situation more closely, we realised that the collapse, initially thought to be impassable, presented a narrow passage between the ice blocks that allowed us to enter a very large gallery. The environments turned out to be morphologically very similar to those found in 2021, but with a general lowering of the gallery.
The exploration allowed us to reach and pass the point where the cave ended on a lake-siphon last year, allowing us to continue towards the heart of the glacier. Only by analysing the topographic survey data will we see that the cave creeps below the glacier for more than 400 m, ending, but only for us explorers, in a new semi-flooded passage at a depth of about 160 m from the entrance.
The cave, however, is not limited to a single conduit and turns out to be much more developed than expected with a maze of large lateral tunnels, all unexplored and interconnected, that are  much larger than the main one. In total, about 950 m of development will be surveyed without taking into account the highly unstable portions of the cave. For the sake of prudence, we did not explore.
On the last day, the activities involved the exploration of the glacial mill, a shaft some twenty metres deep, located on what remains of the glacier's residual tongue, and terminating on the rocky substratum at the base of the glacier itself, where countless collapses prevent the flow of the stream that feeds it from continuing and following. This mill, had already been descended by Alessio, one of our members, over 20 years ago, during the work on his thesis: at that time, it was more or less the same depth and became impenetrable through a narrow passage in the ice. At that time, in the middle of this tongue, which had a very different dimension, there was a mill called G10 about 60 m deep (year 2000) and even this did not reach the rock substrate. This says a lot about how much ice thickness has been lost in recent years and how little time this ice mass has left before the rocky substrate reached the base of the mill this year.
Also on the last day, the Contact Cave Gornersee (CCG) was explored, which is formed every year by a stream flowing down from the lake below the Rosa Hutte. The entrance portal was very wide this year, and the area around it was characterised by the presence of large blocks of ice, which in reality testify to the formation of a temporary lake between glacier and rock, the edges of which are marked by these large 'icebergs'... A photo found on the web later confirmed this hypothesis.
In this area, a huge lake called the Gornersee used to form in spring, accumulating thousands of cubic metres of water, which then disappeared down the valley in just three days through hidden channels in mid-July. In the past, the phenomenon created quite a few problems for Zermatt and the valley populations, now there are canalisation systems to limit the damage. There has been no news of this lake since 2010, but who knows if it will reappear in the future?
A few years ago, Zermatt nevertheless experienced flooding in the summertime, but it was not clear where this water came from.
While this mystery remains unsolved for the time being, we will try to make the most of our efforts to use the data and measurements collected over the years to quantify the impact  that contactcaves have on the mass balance of the glaciers. In the meantime, another year will pass before we see these suffering giants and their changes again, and this 'snapshot' of the state of the glaciers in October 2022 cannot be repeated, but anyone who wants to can take a different one using ours as a comparison.
Between the measurements taken in August, the continuous monitoring of external and internal temperatures, and the 3D surveys carried out over the last two years by VIGEA and Flyability, we really do have a huge amount of data that will now have to be compared and analysed for future scientific publications.



Returning to a glacier is a bit like visiting an old grandfather who lives far away. You realise that he is slowly fading away and you don't know how much longer he will be with you. You are happy, excited, but at the same time a melancholy accompanies you.
In recent years, we often return to the same glaciers and this is the feeling that assails us each time... we see these old grandparents disappearing faster and faster and we are aware that this process is not reversible at the moment!