Time forecast of a break-off event from a hanging glacier

• Published in: The Cryosphere
• Main Authors: J. Faillettaz, M. Funk, M. Vagliasindi
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2016
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Mont Blanc; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-10-1191-2016; https://doaj.org/article/da808b4ac0f048c7885955a03192983f

A cold hanging glacier located on the south face of the Grandes Jorasses (Mont Blanc, Italy) broke off on the 23 and 29 September 2014 with a total estimated ice volume of 105 000 m 3 . Thanks to accurate surface displacement measurements taken up to the final break-off, this event was successfully predicted 10 days in advance, enabling local authorities to take the necessary safety measures. The break-off event also confirmed that surface displacements experienced a power law acceleration along with superimposed log-periodic oscillations prior to the final rupture. This paper describes the methods used to achieve a satisfactory time forecast in real time and demonstrates, using a retrospective analysis, their potential for the development of early-warning systems in real time.