Icequakes coupled with surface displacements for predicting glacier break-off

摘要: A hanging glacier at the east face of Weisshorn (Switzerland) broke off in 2005. We were able to monitor and measure surface motion icequake activity for 25 days up three prior break-off. The analysis seismic waves generated by during rupture maturation process revealed four types precursory signals imminent catastrophic rupture: (i) an increase within glacier, (ii) a decrease waiting time between two successive icequakes, (iii) change size-frequency distribution energy, (iv) modification structure distributions icequakes. Morevover, it was possible demonstrate existence correlation log-periodic oscillations velocities superimposed on global acceleration maturation. Analysis led us identification regimes: stable phase with diffuse damage, unstable dangerous characterized hierarchical cascade instabilities where large icequakes are triggered.