Thinning of the Monte Perdido Glacier in the Spanish Pyrenees since 1981

This paper analyzes the evolution of the Monte Perdido Glacier, the third largest glacier in the Pyrenees, from 1981 to the present. We assessed the evolution of the glacier''s surface area by analysis of aerial photographs from 1981, 1999, and 2006, and changes in ice volume by geodetic methods with digital elevation models (DEMs) generated from topographic maps (1981 and 1999), airborne lidar (2010) and terrestrial laser scanning (TLS, 2011, 2012, 2013, and 2014) data. We interpreted the changes in the glacier based on climate data from nearby meteorological stations. The results indicate that the degradation of this glacier accelerated after 1999. The rate of ice surface loss was almost three times greater during 1999-2006 than during earlier periods. Moreover, the rate of glacier thinning was 1.85 times faster during 1999-2010 (rate of surface elevation change = -8.98 ± 1.80 m, glacier-wide mass balance = -0.73 ± 0.14 m w.e. yr-1) than during 1981-1999 (rate of surface elevation change = -8.35 ± 2.12 m, glacier-wide mass balance = -0.42 ± 0.10 m w.e. yr-1). From 2011 to 2014, ice thinning continued at a slower rate (rate of surface elevation change = -1.93 ± 0.4 m yr-1, glacier-wide mass balance = -0.58 ± 0.36 m w.e. yr-1). This deceleration in ice thinning compared to the previous 17 years can be attributed, at least in part, to two consecutive anomalously wet winters and cool summers (2012-2013 and 2013-2014), counteracted to some degree by the intense thinning that occurred during the dry and warm 2011-2012 period. However, local climatic changes observed during the study period do not seem sufficient to explain the acceleration of ice thinning of this glacier, because precipitation and air temperature did not exhibit statistically significant trends during the study period. Rather, the accelerated degradation of this glacier in recent years can be explained by a strong disequilibrium between the glacier and the current climate, and likely by other factors affecting the energy balance (e.g., increased albedo in spring) and feedback mechanisms (e.g., heat emitted from recently exposed bedrock and debris covered areas)

The Madaleta glacier (Spanish central Pyrenees): an analysis of its evolution since the Little Ice Age and its relationship with climatic factors

[ES] Se analiza el proceso evolutivo del glaciar de la Maladeta (Macizo de la Maladeta-Aneto; Pirineo central español), desde el último máximo de la Pequeña Edad del Hielo hasta la actualidad. Partiendo de distintos elementos disponibles (restos morrénicos, documentos gráficos), se ha reconstruido y cartografiado su extensión en las nueve etapas para las que se cuenta con documentación de validez cronológica contrastada (1820-30; 1857; 1901-04; 1914-20; 1934-35; 1957; 1981; 1990; 1997-99). Esta información se compara con datos climáticos básicos (evolución de temperaturas y precipitaciones), reconstruidos en la zona para ese período mediante la utilización de técnicas dendroclimáticas y complementados por el análisis de registros instrumentales procedentes de varios observatorios surpirenaicos. Los resultados obtenidos permiten confirmar la estrecha relación entre los factores climáticos mencionados y la evolución del glaciar de la Maladeta, que ha pasado de tener una superficie de 152,3 ha en 1820-30, a tan sólo 54,5 ha (la suma de los dos cuerpos actuales) en 1997-99, el 35,7% de la inicial.[EN] The evolution of Maladeta glacier (Maladeta-Aneto massif; Spanish Central Pyrenees) is analized in this work since the last Little Ice Age maximum till today. Using different elements (morainic deposits, graphic documents), the extent of the glacier has been reconstructed and mapped for the nine stages in which reliable chronological data exist (1820-30; 1857; 1901-04; 1914-20; 1934-35; 1957; 1981; 1990; 1997-99). This information is compared with basic climatic data (temperature and precipitation evolution), reconstructed for the zone for that period by using dendroclimatic techniques and complemented by recent instrumental records of several south-pyrenean weather stations. The results thus obtained confirm the control of the above mentioned climatic factors in the evolution of Maladeta glacier, which has receded from an extent of 152.3 ha in 1820-30 to 54.5 ha in 1997-99, a 35.7% of the initial value.Este trabajo forma parte de los proyectos H- 9007 (Estudio de la dinámica de los glaciares del Pirineo aragonés), financiado por el Gobierno de Aragón; UZ2002-HUM-01 (Estudio de la dinámica glaciar en el Pirineo español en el contexto del cambio climático: correlación con re c o n s t ru c c i o - nes dendroclimáticas termo-pluviométricas), financiado por la Universidad de Zaragoza; ECLIPSE (E n v i ronnement et climat du passé: histoire et évo - l u t i o n), financiado por el CNRS; y CLI96-1862 (P recipitaciones y temperaturas de la mitad septen - trional española a partir del siglo XVII. R e c o n s t rucciones dendro c l i m á t i c a s), financiado por la CICYT. Los autores agradecen igualmente las interesantes sugerencias efectuadas por los evaluadores del trabajo, Dres. J.L. Peña y J. Bordonau.Peer reviewe

Responses to climatic changes since the Little Ice Age on Maladeta Glacier (Central Pyrenees)

16 páginas, 14 figuras, 3 tablas.The evolution of Maladeta Glacier (Maladeta massif, central Spanish Pyrenees) since the Little Ice Age maximum is analyzed in this work. The extent of the glacier was mapped into 10 stages using morainic deposits and graphic documents. Climatic data (temperature and precipitation) were reconstructed by using dendroclimatic techniques complemented by recent instrumental records. The results thus obtained confirm the control of the above mentioned climatic factors, particularly annual temperature and winter precipitation, in the evolution of Maladeta Glacier, which has receded from an extent of 152.3 ha in 1820–1830 to 54.5 ha in 2000, a 35.7% reduction in size. The rate of ice wastage has varied during that period, defining several phases of glacial stabilization (1820–1830 to 1857; 1914–1920 to 1934–1935; 1957 to 1981), moderated glacial depletion (1901–1904 to 1914–1920; 1934–1935 to 1957) and marked glacial depletion (1857 to 1901–1904; 1981 to 2000). The evolution of Maladeta Glacier is also in keeping with trends observed from other alpine Mediterranean glaciers, which have experienced a consistent rise in their equilibrium line altitudes during the 19th and 20th centuries as well as associated and prolonged periods of negative mass balance.Financial support for this study was provided by the following research projects: "Estudio de la dinámica de los glaciares del Pirineo aragonés" (H- 9007-2001) funded by the Gobierno de Aragón; "Precipitaciones y temperaturas de la mitad septentrional española a partir del siglo XVII. Reconstrucciones dendroclimáticas" (CLI96-1862) funded by CICYT; and dEstudio de la dinámica glaciar en el Pirineo español en el contexto del cambio climático: correlación con reconstrucciones dendroclimáticas termo-pluviométricasT (UZ2002-HUM-01) funded by Zaragoza University.Peer reviewe

Cartografía de zonas probables de aludes en el Pirineo aragonés: metodología y resultados

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Cartografía de zonas probables de aludes en el Pirineo aragonés: metodología y resultados

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