EGU21-9294
https://doi.org/10.5194/egusphere-egu21-9294
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Volume drop of Pyrenean Glaciers from 2011 to 2020 observed with airborne techniques; LiDAR and SfM

Jesús Revuelto1, Ixeia Vidaller-Gayán1, Eñaut Izagirre2,3, Francisco Eduardo Rojas-Heredia1, Esteban Alonso-González1, Ibai Rico4, Simon Gascoin5, Etienne Berthier6, Pierre Rene7, and Juan Ignacio López-Moreno1
Jesús Revuelto et al.
  • 1Instituto Pirenaico de Ecología, Consejo Superior de Investigaciones Científicas (IPE-CSIC), Zaragoza, Spain (jrevuelto@ipe.csic.es)
  • 2Hydro-Environmental Processes Research Group, Geology Department, University of the Basque Country UPV/EHU, Leioa, Spain
  • 3Basque Centre for Climate Change BC3, Leioa, Spain
  • 4Department of Geography, Prehistory, and Archaeology. University of the Basque Country. Vitoria-Gasteiz. Spain.
  • 5Centre d'Etudes Spatiales de la Biosphère, CESBIO, Univ. Toulouse, CNES/CNRS/INRAE/IRD/UPS, 31401 Toulouse, France
  • 6LEGOS, Université de Toulouse, CNES, CNRS, IRD, UPS, France
  • 7MORAINE Association Pyrénéenne de Glaciologie

Pyrenean glaciers are one of the southernmost glaciers in Europe. These ice bodies have suffered a fast retreat in the last decades mainly caused by the temperature increase of the last century. Here, we use state of the art airborne techniques to present the most complete evaluation of glacier volume change from 2011 to 2020.

In 2011 the Spanish Geographical Institute covered the entire country with airborne LiDAR. The glacier topography on the Spanish side of the Pyrenees (and also several hundreds of meters beyond the French border) was retrieved between September and November, when snow cover was minimal. In autumn 2020, we used different Unmanned Aerial Vehicles to survey 17 out of the 19 Pyrenean glaciers. The images acquired in these flights were processed with Structure from Motion algorithms to reconstruct the Digital Surface Model (DSM) in 3D of the glacier surfaces and nearby terrain.

Differencing of the DSM in 2011 and 2020 reveals a drastic retreat and volume loss. The mean elevation drop is 7 m, some glaciers had losses of more than 12 m in average with a surface lowering of more than 20 m locally. The mean annual mass balance observed when considering the 2D projection of glaciers surface was -1.83 m w.e./yr. Taking into account the true glaciers extent from the 3D surface retrieved from the UAV observations, the annual mass balance decreases to -1.30 m w.e./yr. The difference between these mass balances highlights the impact that utilising close range remote sensing observations have, when compared to satellite acquisitions, to accurately observe glaciers evolution in steep mountain areas.

How to cite: Revuelto, J., Vidaller-Gayán, I., Izagirre, E., Rojas-Heredia, F. E., Alonso-González, E., Rico, I., Gascoin, S., Berthier, E., Rene, P., and López-Moreno, J. I.: Volume drop of Pyrenean Glaciers from 2011 to 2020 observed with airborne techniques; LiDAR and SfM, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9294, https://doi.org/10.5194/egusphere-egu21-9294, 2021.

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