Project

Back to overview

Development of Earthquake Source Physics Models for the seismological assessment of future earthquakes and ground motion prediction in the Alpine regions

English title Development of Earthquake Source Physics Models for the seismological assessment of future earthquakes and ground motion prediction in the Alpine regions
Applicant Dalguer Luis
Number 129562
Funding scheme Project funding
Research institution Institut für Geophysik ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Geophysics
Start/End 01.05.2010 - 31.08.2013
Approved amount 177'338.00
Show all

Keywords (6)

earthquake rupture dynamic; earthquake source physics; friction models; near-source ground motion; ground motion prediction; simulation-based seismic hazard

Lay Summary (English)

Lead
Lay summary
Earthquake numerical models based on physics of the causative rupture and wave propagation, incorporating conservation laws of continuum mechanics, frictional sliding, and the state of stress in the crust, have expanded our understanding of both source- and propagation-dominated ground motion phenomena. In the present project we propose to develop suite of earthquake source physics-based numerical models to study rupture dynamic complexity and the resulted near-source ground motion, implementing laboratory-based constitutive friction models for different geological structures in the Alpine regions, for the seismological assessment of past and future earthquakes and ground motion prediction in the Alpine regions. Motivated by recent realistic high velocity friction experiments, we plan to use a strongly rate-weakening friction law formulated in a rate-and-state framework. This friction model, not yet studied in realistic geological condition and heterogeneous stress distribution, is a generalized friction model and proven to be a promising model to study earthquake realistically.The Swiss Alps, specifically the Valais area has the largest seismic hazard in Switzerland, has experienced a magnitude 6 or larger event every 100 years, with the last magnitude 6.1 earthquake in 1946 close to Sion and Sierre. Besides this seismic activity, the Valais present rough topography, unstable and steep slopes, deep sediment-filled valleys, wide glacier- and snow-covered areas that potentially increase the seismic risk level due to earthquake-induced natural disaster such as liquefaction, landslides, rock and snow avalanches. In addition, important critical facilities of Switzerland, such as hydroelectric power plants and chemical plants have been built in the Valais, making the region even more vulnerable to damaging earthquake. Considering that the probability of observing a major earthquake (up to magnitude 6.5) in the next 40 years in the region is high, it is wisdom to be prepared to this earthquake. The earthquake physics models developed for this area, will provide a better physical understanding of how earthquakes operate in this area, and consequently it will help to improve our capability for ground motion prediction for the assessment of seismic hazard and to mitigate the seismic risk in the area. Furthermore this site-specific study will contribute to the evaluation of the critical facilities installed in this area, contributing to improved seismic safety of future and existing structures.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Fault zone signatures from ambient vibration measurements - a case study in the region of Visp
Baumann Cyrill, Burjanek Jan, Michel Clotaire, Haeh Donat, Dalguer Luis, Fault zone signatures from ambient vibration measurements - a case study in the region of Visp, in Swiss Journal of Geosciences.

Abstract

Earthquake numerical models based on physics of the causative rupture and wave propagation, incorporating conservation laws of continuum mechanics, frictional sliding, and the state of stress in the crust, have expanded our understanding of both source- and propagation-dominated ground motion phenomena. Some examples, that bear directly on strong motion simulation, are: 1) buried ruptures may generate stronger high frequency ground motion than surface-rupturing earthquakes do; 2) incoherence of rupture propagation may reduce the rupture directivity pulses; 3) velocity pulses induced by supershear rupture may produce large amplitude ground motion; 4) wave propagation models show that local geology effects can enhance ground motion in basins through several mechanisms, including energy channeling.The assessment of these mechanisms that have been identified in physics-based numerical simulations are required if we are to adequately evaluate the level and variability of near-source ground motion, for potential expected events in a specific zone, for seismic hazard and seismic risk mitigation.In the present project we propose to develop suite of earthquake source physics-based numerical models to study rupture dynamic complexity and the resulted near-source ground motion, implementing laboratory-based constitutive friction models for different geological structures in the Alpine regions, for the seismological assessment of past and future earthquakes and ground motion prediction in the Alpine regions. Motivated by recent realistic high velocity friction experiments, we plan to use a strongly rate-weakening friction law formulated in a rate-and-state framework. This friction model, not yet studied in realistic geological condition and heterogeneous stress distribution, is a generalized friction model and proven to be a promising model to study earthquake realistically.The Swiss Alps, specifically the Valais area has the largest seismic hazard in Switzerland, has experienced a magnitude 6 or larger event every 100 years, with the last magnitude 6.1 earthquake in 1946 close to Sion and Sierre. Besides this seismic activity, the Valais present rough topography, unstable and steep slopes, deep sediment-filled valleys, wide glacier- and snow-covered areas that potentially increase the seismic risk level due to earthquake-induced natural disaster such as liquefaction, landslides, rock and snow avalanches. In addition, important critical facilities of Switzerland, such as hydroelectric power plants and chemical plants have been built in the Valais, making the region even more vulnerable to damaging earthquake. Considering that the probability of observing a major earthquake (up to magnitude 6.5) in the next 40 years in the region is high, it is wisdom to be prepared to this earthquake. The earthquake physics models developed for this area, will provide a better physical understanding of how earthquakes operate in this area, and consequently it will help to improve our capability for ground motion prediction for the assessment of seismic hazard and to mitigate the seismic risk in the area. Furthermore this site-specific study will contribute to the evaluation of the critical facilities installed in this area, contributing to improved seismic safety of future and existing structures.
-