Premium
Climate warming revealed by englacial temperatures at Col du Dôme (4250 m, Mont Blanc area)
Author(s) -
Vincent Christian,
Le Meur Emmanuel,
Six Delphine,
Possenti Philippe,
Lefebvre Eric,
Funk Martin
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl029933
Subject(s) - borehole , meltwater , glacier , geology , climatology , environmental science , altitude (triangle) , atmospheric sciences , geomorphology , geometry , geotechnical engineering , mathematics
Temperatures were measured in two deep boreholes drilled at the same location in the ice at Col du Dôme (4250 m) in 1994 and 2005, providing clear evidence of atmospheric warming. The 1994 temperature profile was already far from steady state conditions. Results from a heat transfer model reveal that the englacial temperature increase cannot be explained solely by atmospheric temperature rise. The latent heat produced by the refreezing of surface meltwater below the surface also contributes to the englacial temperature increase. Although surface melting is normally very low at this altitude, this contribution became significant after 1980 for temperatures at the top of the borehole. Simulations for different climatic scenarios show that glaciated areas located between 3500 and 4250 m could become temperate in the future. This warming could have a major impact on the stability of hanging glaciers frozen to their beds if the melting point is reached.