Age of the Mt. Ortles ice cores, the Tyrolean Iceman and glaciation of the highest summit of South Tyrol since the Northern Hemisphere Climatic Optimum - Archive ouverte HAL
Article Dans Une Revue The Cryosphere Année : 2016

Age of the Mt. Ortles ice cores, the Tyrolean Iceman and glaciation of the highest summit of South Tyrol since the Northern Hemisphere Climatic Optimum

Paolo Gabrielli
  • Fonction : Auteur
Carlo Barbante
Giuliano Bertagna
  • Fonction : Auteur
Michele Bertó
Daniel Binder
  • Fonction : Auteur
Alberto Carton
  • Fonction : Auteur
Luca Carturan
  • Fonction : Auteur
Federico Cazorzi
  • Fonction : Auteur
Giulio Cozzi
  • Fonction : Auteur
Giancarlo Dalla Fontana
  • Fonction : Auteur
Mary Davis
  • Fonction : Auteur
Fabrizio de Blasi
  • Fonction : Auteur
Roberto Dinale
  • Fonction : Auteur
Gianfranco Dragà
  • Fonction : Auteur
Giuliano Dreossi
  • Fonction : Auteur
Daniela Festi
Massimo Frezzotti
Jacopo Gabrieli
  • Fonction : Auteur
Stephan Galos
  • Fonction : Auteur
Petra Heidenwolf
  • Fonction : Auteur
Theo Jenk
Natalie Kehrwald
  • Fonction : Auteur
Donald Kenny
  • Fonction : Auteur
Olivier Magand
  • Fonction : Auteur
Volkmar Mair
  • Fonction : Auteur
Vladimir Mikhalenko
  • Fonction : Auteur
Ping Nan Lin
  • Fonction : Auteur
Klaus Oeggl
  • Fonction : Auteur
Gianni Piffer
  • Fonction : Auteur
Mirko Rinaldi
  • Fonction : Auteur
Ulrich Schotterer
  • Fonction : Auteur
Margit Schwikowski
Roberto Seppi
Andrea Spolaor
Barbara Stenni
David Tonidandel
  • Fonction : Auteur
Chiara Uglietti
  • Fonction : Auteur
Victor Zagorodnov
  • Fonction : Auteur
Thomas Zanoner
  • Fonction : Auteur
Piero Zennaro
  • Fonction : Auteur

Résumé

Abstract. In 2011 four ice cores were extracted from the summit of Alto dell'Ortles (3859 m), the highest glacier of South Tyrol in the Italian Alps. This drilling site is located only 37 km southwest from where the Tyrolean Iceman, ∼ 5.3 kyrs old, was discovered emerging from the ablating ice field of Tisenjoch (3210 m, near the Italian–Austrian border) in 1991. The excellent preservation of this mummy suggested that the Tyrolean Iceman was continuously embedded in prehistoric ice and that additional ancient ice was likely preserved elsewhere in South Tyrol. Dating of the ice cores from Alto dell'Ortles based on 210Pb, tritium, beta activity and 14C determinations, combined with an empirical model (COPRA), provides evidence for a chronologically ordered ice stratigraphy from the modern glacier surface down to the bottom ice layers with an age of ∼ 7 kyrs, which confirms the hypothesis. Our results indicate that the drilling site has continuously been glaciated on frozen bedrock since ∼ 7 kyrs BP. Absence of older ice on the highest glacier of South Tyrol is consistent with the removal of basal ice from bedrock during the Northern Hemisphere Climatic Optimum (6–9 kyrs BP), the warmest interval in the European Alps during the Holocene. Borehole inclinometric measurements of the current glacier flow combined with surface ground penetration radar (GPR) measurements indicate that, due to the sustained atmospheric warming since the 1980s, an acceleration of the glacier Alto dell'Ortles flow has just recently begun. Given the stratigraphic–chronological continuity of the Mt. Ortles cores over millennia, it can be argued that this behaviour has been unprecedented at this location since the Northern Hemisphere Climatic Optimum.
Fichier principal
Vignette du fichier
tc-10-2779-2016.pdf (6.29 Mo) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-04704179 , version 1 (23-09-2024)

Licence

Identifiants

Citer

Paolo Gabrielli, Carlo Barbante, Giuliano Bertagna, Michele Bertó, Daniel Binder, et al.. Age of the Mt. Ortles ice cores, the Tyrolean Iceman and glaciation of the highest summit of South Tyrol since the Northern Hemisphere Climatic Optimum. The Cryosphere, 2016, 10 (6), pp.2779-2797. ⟨10.5194/tc-10-2779-2016⟩. ⟨hal-04704179⟩
27 Consultations
3 Téléchargements

Altmetric

Partager

More