The Glaciers of the Pyrenees

Mar 11, 2021 | 2021, EFGeoBlog

The Pyrenees mountain range is a geographical feature located in southwestern Europe, lying across the border between Spain, France and Andorra (Figure 1). The range runs from the Atlantic Ocean (Gulf of Biscay) to the Mediterranean Sea (Gulf of Leon) with a W–E orientation. It is a narrow range, almost 500 km long and 80 km wide.

Figure 1: Satellite image of the Pyrenees mountain range, the natural border between Spain and France. The yellow pins mark the exact locations of glaciers. Own elaboration with the Google Earth programme.

The Pyrenees were formed between the Upper Cretaceous and the Lower Miocene, due to the collision of the Euro-Asiatic and Iberian plates (Teixell, 2019). In consequence, some of the region’s highest peaks are located more than 3000m above sea level, with Aneto’s peak having the highest summit at 3404 m.

Thus, these are the most southerly glaciers within Europe; they have developed on both faces of the mountain range between 42º and 43º latitude (Figure 2). However, they are confined to the highest and darkest parts of the mountain range. 

Figure 2: Locations of the 19 glaciers at larger scale. They are numbered from west to east. Made with the Google Earth programme.

The glaciers are permanent ice masses that can flow and deform due to their own weight. Moreover, they crawl due to the effect of gravity; they are dynamic bodies with the capacity to move slowly down slope. They grow and get input from proximal areas, and they lose mass through ablation with fusion in distal areas.

The glaciers of the Pyrenees, in general, are characterised by their small size. They lie in mountain cirques without developing the glacier tongues that typically form in glaciers in northern areas such as the Alps, the Caucasus, etc. In Table 1, all current glaciers are shown with some of their main characteristics, such as altitude, orientation and area. Currently, there are 19 glaciers within 9 massifs.

Table 1: Table where the glaciers are listed by massif, including information about their main features. Data sources: Google Earth, Iberpix, WGMS.

Describing all of the glaciers would be outside the scope of this article, which is intended to highlight the importance of this ecosystem. Instead,the article outlines the four largest glaciers.

1. The Ossoue glacier (Figure 3) is located in the Vignemale massif at the border between France and Spain. It lies on the east face of the Vignemale peak and is one of the biggest glaciers in the Pyrenees. It has an extent of 37.22 ha. It has maintained considerable thickness and movement activity; however, it has had small fragmentations since 2016.

Figure 3: The Ossoue glacier from the air. At the bottom of the picture, it is possible to see strain cracks on the ice surface. © Jordi Camins Just.

2. The Monte Perdido glacier rests in the homonymous massif, the highest calcareous massif in Europe (Figure 4). This is one of the most famous, walked and studied glaciers in the range. It has a surface area of 37.77 ha, which makes it the second biggest glacier in the Pyrenees. It is on the east face of Monte Perdido’s peak. Unfortunately, it has suffered some fragmentation and has lost some thickness (López-Moreno et al., 2007).

Figure 4: Detailed view of the Monte Perdido glacier taken in July 2016. At this time of year, snow still covers most of the ice. © Alberto Sánchez Miravalles.

3. The Maladeta glacier (Figure 5A) is the fourth biggest in the Pyrenees, covering 29.83 ha. It is located on the north face of Maladeta’s peak and it still has many cross-cracks and a small ice tongue that extends downwards 200 m.

4. The Aneto glacier is the biggest in the whole mountain range (56.1 ha). It has a N–NE orientation and, as with most glaciers, it has had regressions since the Little Ice Age (LIA). It has lost half of its ice surface in the last century (Camins, 2010). Recently, splitting and fragmentation occurred in its eastern part, which supports the signs of regression. However, it still has big cracks and a small randkluft (Figure 5B).

Figure 5: A: In the foreground on the right side is the Maladeta glacier with significant traction cracks. B: The Aneto glacier lying under the Del Medio, Coronas and Aneto peaks. Summer 2019. © Gerardo Bielsa.

The glaciers establish a resource and source of fresh water, important for the water bodies (rivers, creeks, springs, dams) running down both mountain sides. Without this water supply, these water bodies might get dry in the summer months, when temperatures are higher.

Moreover, the snow cover helps to reflect part of the solar radiation, which tends to balance the local climate.

Some recent studies remark that this ecosystem is fragile, and it has lost a big surface area since the end of the LIA. In 1850, the total extent of the glaciers of the Pyrenees was around 2060 ha (René, 2013); however, the total extent was dramatically reduced to 242 ha in 2016 (Rico et al., 2016). This meant an 88% reduction of the ice surface (Figure 6). In addition, the number of glaciers has been reduced too, from 52 in 1850 to 19 nowadays.

this ecosystem is fragile, and it has lost a big surface area since the end of the LIA.

Figure 6: Variation in the glacial area in the Pyrenees from 1850 to the present (2016). The horizontal axis is not at uniform scale. Own elaboration, data source: Rico et al., 2016.

The glaciers are a natural treasure that we should keep at any cost, letting our future generations know them and enjoy them.

The continuous ice loss since more than 150 years ago indicates that the glaciers of the Pyrenees are in a state of regression. Moreover, the increase in the annual average temperature is accelerating the process.

Those changes are particularly dramatic in transition climatic areas (Atlantic–Mediterranean); because of the fragility of the ecosystem, these glaciers are much more vulnerable than others situated in northern areas.

For the reasons shown above, the glaciers of the Pyrenees constitute a natural lab where it is possible to study how the climate is changing. By monitoring the total ice mass, scientists like geologists, biologists or glaciologists can anticipate what will happen in other areas in the future if the climate follows this warming trend. The glaciers are a natural treasure that we should keep at any cost, letting our future generations know them and enjoy them.

If you want to know further details about the glaciers in the Pyrenees, click this link to go to the source article (in Spanish).


  • Camins, J. 2010. El Glaciar de Aneto. Efectos del Cambio Climático en Imágenes. Besa & Keops S.L.168 pp.
  • López-Moreno, J.I., Revuelto, J.,Rico, I.,Chueca-Cia, J.,Julián, A., Serreta, A., Serrano, E., Vicente-Serrano, S.M., Azorín-Molina, C., Alonso-González, E.,& García-Ruíz, J.M. 2016. Thinning of the Monte Perdido Glacier in the Spanish Pyrenees since 1981. The Cryosphere, 10.681–694. DOI: 10.5194/tc-10-681-2016
  • René, P. 2013. Glaciers des Pyrénées: Le réchauffement climatique en images. Ed. Cairn. 167 pp., Pau.
  • Rico, I., Izagirre, E., Serrano, E.,& López-Moreno, J.I. 2017. Current glacier area in the Pyrenees: an updated assessment 2016. Pirineos, e029. DOI:
  • Teixell, A., Arboleya, M.L.,& Barnolas, A.2019.Tectonica de cabalgamientos y sedimentación sinorogénica en el Pirineo centro-occidental. Geo-Guías,11. Mayo 2019. Sociedad Geológica de España.

Alberto Sanchez Miravalles is a Spanish Geologist with several post-grades courses in Geotechnical and Oil & Gas Engineering in Complutense and Politécnica universities of Madrid, respectively. Alberto has international experience and good skills in exploration, rock mechanics, water remediation and geotechnics. Nowadays, he is working for the European Federation of Geologists in Brussels as a project officer in charge of the management of EU projects. Besides, Alberto collaborates with the ICOG (Spanish Association of Professional Geologists), as courses developer and online teacher.

Contributor: Alberto Sanchez Miravalles

European Federation of Geologists

Ratko Vasiljević has more than twenty years of work experience at the environmental protection company ECOINA, Zagreb, Croatia, at soil, air, surface water and groundwater protection and remediation. Since 2014, he works on the implementation of ISO 14065 standards for Greenhouse gases verification. He obtained diploma (1998) and PhD (2012) in the field of Geology and Geological Engineering at the Faculty of Mining, Geology and Petroleum engineering, University of Zagreb. In 2019 he was nominated as an Expert Witness for Geology research by the County Court in Zagreb.

Contributor: Ratko Vasiljević


Disclaimer: This article expresses the personal opinions of the author. These opinions may not reflect the official position of the European Federation of Geologists (EFG).