Glacial Hazard Monitoring With Seismology Host: Laboratory of Hydraulics, Hydrology and Glaciology VAW ETH Zürich (at work) Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University, USA

Can we predict destructive glacier failure? Unteraargletscher, BE Raymond et al. (2003) Unteraargletscher, BE Allalingletscher, VS (1965)

Weisshorn (4505 m), VS “Hanging Glaciers” Frozen to bed Steep glacier tongue Sliding bed Subglacial hydraulics Radar? Resolution problem? Raymond et al. (2003)

Gornersee, VS 1.2 km Ice dam failure Rock Glacier

Early Warning Seismic noise measured in situ Monitoring limitations Surface targeted, only Seismic noise measured in situ “See” into the glacier Fracture state Basal drainage

Hanging Glaciers: Natural Frequency collegevibe.com Milikan Library, California Stiffness K Material quality Structural damage Monitoring

Chamousset Rock Column, France (Levy et al. , 2010; Bottelin et al Hanging Glaciers Break-off Resonance peak monitoring Early warning sign Volume estimate Directional Fourier Transform Frequency (Hz) Resonance Peaks Frequency decay prior to failure Flexure mode

Monitoring of Ice Dam Fractures Walter et al., submitted to GJI Monitoring of Ice Dam Fractures Rock Glacier Seismic Noise Interferometry  Cross-correlation  Seismic noise monitoring “Virtual hammer blows”: No hammer needed! Idea: ice dam monitoring Hammer blow  Force impulse Fracture state  seismic velocities

Steep Glacier Tongues: Seismic Water Tremor Roger Braithwaite, U Manchester 15 hours Frequency (Hz) 5 10 15 Pressure Water Röösli et al. (2014), Walter et al. (submitted) Matched filter processing

Can Distant Earthquakes Trigger Glacier Failure? Source: USGS Landslide in Alaska Range after M7.9 2002 Denali Fault earthquake Digital seismic records at host institute Triggered Glacier Failure? 2005 Weisshorn break-off only three days after 9th largest earthquake since 1990 (M8.6 in Indonesia) Induced crevasse opening in Antarctica (Peng et al. (2014) in ngeo) Glaciers at tipping point? Search digital seismic records for earthquake-induced fractures

Implementation WIRELESS FREE 23 cm 80 cm Instrument installation Hanging glacier Steep glacier tongue Ice dam 23 cm Geopebble (Penn State) WIRELESS 80 cm Conventional glacier installation FREE

… Implementation 2 PhD Students 1 field engineer Tasks Tool translation to glaciers Data analysis Instrument installation 2 PhD Students Enough data, fieldwork, subprojects for master’s students …

Seismology Natural Glaciology Hazards Host Institute: Laboratory of Hydraulics, Hydrology and Glaciology VAW (ETH Zurich) Seismic Noise U Grenoble UC San Diego Stanford USGS ETH-Internal Collaboration Swiss Seismological Service Geophysical Institute Seismology Earthquake Triggering UC San Diego Georgia Tech VAW Since 1970’s Field experience Natural Hazards Glaciology Fieldwork, instruments U Grenoble Penn State

Career Goal: Faculty Position Fieldwork Stability Hydraulics Damage Mechanics GPS Photogrammetry Radar interferometry Early warning systems Engineering seismology Noise Sensor installation Finite element modeling Data handling Seismology Natural Hazards Glaciology Teaching: Physics of Glaciers

Thank you for your attention!

Weisshorn: Continuous Spectrograms

Glacier Seismology Glacier Seismology Podolskiy and Walter, in prep.

Career Outlook in Switzerland NATURAL HAZARDS GLACIER SEISMOLOGY Seismic detection of debris flow/landslide/snow avalanche detection and early warning Swiss Federal Institute for Forest, Snow and Landscape Research WSL: ETH Zurich: Assistant professor in engineering glaciology Lausanne: Institut de Géographie et Durabilité SLF Uni Berne: Institute of Geological Sciences

Steep Glacier Tongues: “Active” Phases Röthlisberger and Kasser (1978) Efficient subglacial drainage:  Melt-suppressed sliding Inefficient subglacial drainage:  Melt-enhanced sliding

Digital Seismic Records at ETH (since 1997) Alpine Glacier Seismology Collaboration VAW- Swiss Seismological Service Altogether over 3 years of continuous seismic records

Can Earthquakes Cause Glacier Failure? Peng et al. (2014) Nature Geoscience Dynamic Fracturing Search glacier seismic records for earthquake-triggered icequakes Crevassing events triggered by earthquake surface waves