Réf. Schiermeier 2003 - A

Référence bibliographique complète

SCHIERMEIER Q. Alpine thaw breaks ice over permafrost's role. Nature, 2003, Vol. 424, p. 712


Mots-clés
Heatwave, summer 2003, permafrost thawing, rockfalls

Organismes / Contact
 

(1) - Paramètre(s) atmosphérique(s) modifié(s)
(2) - Elément(s) du milieu impacté(s)
(3) - Type(s) d'aléa impacté(s)
(3) - Sous-type(s) d'aléa
Temperature Permafrost   Rockfalls / Rockslides

Pays / Zone
Massif / Secteur
Site(s) d'étude
Exposition
Altitude
Période(s) d'observation
Alps          

(1) - Modifications des paramètres atmosphériques
Reconstitutions
 
Observations
 
Modélisations
 
Hypothèses
 

Informations complémentaires (données utilisées, méthode, scénarios, etc.)

 


(2) - Effets du changement climatique sur le milieu naturel
Reconstitutions
 
Observations

Europe:
There is clear evidence for accelerated thawing in the upper permafrost layer in many regions. Researchers in the European Union-funded Permafrost And Climate in Europe project (PACE) have found evidence of temperature increases of between 0.5 and 2.0 °C over the past 60-80 years in permafrost soils in European mountain regions, from the Sierra Nevada in Spain to the arctic archipelago of Spitsbergen (C. Harris, Permafrost and Periglacial Processes, 2001).

Alps:
As in 2003 Europe swelters in one of its hottest summers since records began, the heat is making itself felt in the high Alps, where thawing ice is destabilizing landscapes that are normally frozen. In the Alps, most ground above an altitude of 2,500 metres remains frozen throughout the year, with only a surface layer less than 5 metres thick melting in the summer and re-freezing in winter. Above 3,000 metres, temperatures rarely exceed 0°C for any length of time during the summer. During summer 2003, however, ice bas been thawing out steadily at altitudes of up to 4,600 metres.

Modélisations
 
Hypothèses
Researchers who study permafrost say that the patterns of disruption being seen in the Alps during 2003 could soon be replicated on a larger scale, with global warming eroding the quarter of the Earth's land surface that is permanently frozen.

If heavy snow in the winter insulates the ground from low air temperatures, permafrost can thaw even more deeply in summer.

Sensibilité du milieu à des paramètres climatiques
Informations complémentaires (données utilisées, méthode, scénarios, etc.)
   

(3) - Effets du changement climatique sur l'aléa
Reconstitutions
 
Observations
According to observation of permafrost temperature and slope stability at 26 drilling sites throughout the Swiss Alps (PERMOS), there is a large variability, due to differences in topography, but by and large the threat of slope failure is increasing.
Modélisations
 
Hypothèses
 

Paramètre de l'aléa
Sensibilité du paramètres de l'aléa à des paramètres climatiques
Informations complémentaires (données utilisées, méthode, scénarios, etc.)
 
 

(4) - Remarques générales

 


(5) - Syntèses et préconisations