glacial hazard monitoring with seismology fabian walter 2009 – dr. sc. eth zürich 2004 – msc...
TRANSCRIPT
![Page 1: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/1.jpg)
Glacial Hazard MonitoringWith Seismology
Fabian Walter2009 – Dr. sc. ETH Zürich2004 – MSc University of Colorado, USA2002 – BSc Brigham Young University, USA
Host: Laboratory of Hydraulics, Hydrology and Glaciology VAWETH Zürich
(at work)
![Page 2: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/2.jpg)
Can we predictdestructiveglacier failure?
Raymond et al. (2003)
Allalingletscher, VS (1965)Unteraargletscher, BE
![Page 3: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/3.jpg)
Weisshorn (4505 m), VS
“Hanging Glaciers”Frozen to bed
Steep glacier tongue• Sliding bed• Subglacial hydraulics
Raymond et al. (2003)
![Page 4: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/4.jpg)
Gornersee,VS
Rock Glacier
Ice dam failure
1.2 km
![Page 5: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/5.jpg)
Early Warning
Monitoring limitationsSurface targeted, only
“See” into the glacier• Fracture state• Basal drainage Seismic noise
measured in situ
![Page 6: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/6.jpg)
Hanging Glaciers: Natural Frequency
Stiffness K• Material quality• Structural damage• Monitoring
collegevibe.com
Milikan Library, California
![Page 7: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/7.jpg)
Chamousset Rock Column, France(Levy et al., 2010; Bottelin et al., 2013)
Hanging Glaciers Break-off• Resonance peak monitoring• Early warning sign• Volume estimate
Resonance Peaks• Frequency decay
prior to failure• Flexure mode
Directional Fourier Transform
Frequency (Hz)
![Page 8: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/8.jpg)
Monitoring of Ice Dam Fractures Rock Glacier
Fracture state seismic velocities
Seismic noise monitoring• “Virtual hammer blows”:
No hammer needed!• Idea: ice dam monitoringHammer blow Force impulse
Seismic Noise Interferometry
Cross-correlation
Walter et al., subm
itted to G
JI0
![Page 9: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/9.jpg)
Steep Glacier Tongues: Seismic Water Tremor
Roger Braithwaite, U Manchester
15 hours
Freq
uenc
y (H
z)
5
10
15
Wat
erPr
essu
re
Röös
li et
al.
(201
4), W
alte
r et a
l. (s
ubm
itted
)
Matched filter processing
![Page 10: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/10.jpg)
Source: USGS
Can Distant Earthquakes TriggerGlacier Failure?
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?
Landslide in Alaska Range afterM7.9 2002 Denali Fault earthquake
Search digital seismic records for earthquake-induced fractures
Digital seismic records at host institute
![Page 11: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/11.jpg)
Implementation
23 cm
Geopebble (Penn State)
FREEW
IRELESS
Instrument installation• Hanging glacier• Steep glacier tongue• Ice dam
80 cm
Conventional glacier installation
![Page 12: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/12.jpg)
Implementation
2 PhD Students Enough data, fieldwork, subprojects for master’s students
…
1 field engineerTasks1. Tool translation to glaciers2. Data analysis3. Instrument installation
![Page 13: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/13.jpg)
Host Institute: Laboratory of Hydraulics, Hydrology and Glaciology VAW
(ETH Zurich)
Seismology
Glaciology Natural
Hazards
Seismic Noise• U Grenoble• UC San Diego• Stanford• USGS
VAW• Since 1970’s• Field experience
Earthquake Triggering• UC San Diego• Georgia Tech
Fieldwork, instruments• U Grenoble• Penn State
ETH-Internal Collaboration• Swiss Seismological Service• Geophysical Institute
![Page 14: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/14.jpg)
Career Goal: Faculty Position
Teaching: Physics of GlaciersGlaciology Natu
ral
Hazards
Seismology
Fieldwork
Stability
Hydraulics
DamageMechanics
GPS
Photogrammetry
Radarinterferometry
Early warningsystems
Engineeringseismology
Noise interferometry
SensorinstallationFinite element
modeling Data handling
![Page 15: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/15.jpg)
Thank you foryour attention!
![Page 16: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/16.jpg)
Weisshorn: Continuous Spectrograms
![Page 17: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/17.jpg)
Glacier Seismology
Glacier Seismology
Podo
lski
y an
d W
alte
r, in
pre
p.
![Page 18: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/18.jpg)
Career Outlook in Switzerland
GLACIER SEISMOLOGYNATURAL HAZARDS
ETH Zurich:Assistant professor in engineering glaciology
Seismic detection of debris flow/landslide/snow avalanche detection and early warningSwiss Federal Institute for Forest, Snow and Landscape Research WSL:
SLF Uni Berne: Institute of Geological Sciences
Lausanne: Institut de Géographie et Durabilité
![Page 19: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/19.jpg)
Steep Glacier Tongues: “Active” Phases
Röthlisberger and Kasser (1978)
Efficient subglacialdrainage: Melt-suppressed sliding
Inefficient subglacialdrainage: Melt-enhanced sliding
![Page 20: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/20.jpg)
Digital Seismic Records at ETH (since 1997)
Alpine Glacier Seismology• Collaboration VAW- Swiss Seismological Service• Altogether over 3 years of continuous
seismic records
![Page 21: Glacial Hazard Monitoring With Seismology Fabian Walter 2009 – Dr. sc. ETH Zürich 2004 – MSc University of Colorado, USA 2002 – BSc Brigham Young University,](https://reader036.vdocument.in/reader036/viewer/2022062714/56649d0d5503460f949e1f1a/html5/thumbnails/21.jpg)
Can Earthquakes Cause Glacier Failure?
Peng et al. (2014)Nature Geoscience
Dynamic FracturingSearch glacier seismic records for earthquake-triggered icequakes
Crevassing events triggered by earthquake surface waves