The Potential for a Uniform, Testable, Global Seismic Hazard Model Graeme. Weatherill
-
Upload
global-earthquake-model-foundation -
Category
Technology
-
view
1.043 -
download
0
description
Transcript of The Potential for a Uniform, Testable, Global Seismic Hazard Model Graeme. Weatherill
The Potential for a Uniform, Testable, Global Seismic Hazard Model
Graeme. Weatherill1, M. Pagani1, P. Bird2, C. Kreemer3, D. Monelli4, D. Jackson2, Y. Kagan2, R. Stein5, Powell Working Group
1Global Earthquake Model Facility, Pavia2UCLA, Los Angeles, CA3U. Nevada, Reno, NV4Global Earthquake Model Facility, ETH, Zurich5United States Geological Survey, Menlo Park, CA
A Globally “Uniform”
Seismic Hazard Model
(GEM) Global Component Datasets
Testing & Evaluation
Spatially homogenous
Scientific Innovation
High Resolution (0.1˚ ×0.1˚)
Transparent & Replicable
Global Earthquake Activity Rate (GEAR) Model
‣ A hybrid strain/smoothed seismicity approach
Smoothed Seismicity
Global Strain
Earthquake Recurrence Model
Smoothing Process
Depth/ Mechanism
Earthquake Recurrence Model
• Branches are not completely independent!
• Strain may help provide long term stationarity
Depth/ Mechanism Testing &
Evaluation
Global Smoothed Seismicity Model
Global Seismicity Forecast (end‐2012) (Kagan & Jackson, 2010)
From Strain Rate to Seismicity Rate – A Global “SHIFT”‣ Seismic Hazard inferred from Tectonics “SHIFT” (Bird & Liu, 2007;
Bird et al. 2010)
‣ Seismic Moment Rate (M) from Strain Rate:
Incompressible:
At the ground surface:
Ordered:
<cz> = Coupled Depth (km)μ = Shear Modulus (GPa)
Coupled Seismogenic Volume
A
From Strain Rate to Seismicity Rate – A Global “SHIFT”
‣ Model parameters specific to tectonic region class (Bird & Kagan, 2004):‒ Coupled seismogenic thickness (<cz>)‒ exponent (β) & corner magnitude (mc)
Intraplate (IPL)
Continental Rift Boundary (CRB)
Continental Transform Fault (CTF)
Continental Convergent Boundary (CCB)
Ocean Spreading Ridge (OSR)
Ocean Transform Fault (OTF)
Oceanic Convergent Boundary (OCB)
Subduction
Seismicity Rate from Strain Rate (SHIFT)
Hybrid (Strain + Smoothed Seismicity) Model
Weighted with Smoothed Seismicity (0.625) and Strain (0.375)
From GEAR to Global Hazard …
Seismic Hazard Input Model
Global Activity Rate Model
Source Geometry
Magnitude Scaling Relation
Depth Distribution
Focal Mechanism
Upper Bound Magnitude Ground Motion
Prediction Equations (GMPE)
GMPE Logic Tree
Probability‐Based Upper Bound on Magnitude
Upper Bound Magnitude at Annual Probability of Exceedence ≥ 10‐6
Ground Motion Prediction Equations (GMPEs)
Active Shallow Crust
Subduction
Stable Continental
Akkar & Bommer (2010)
Chiou & Youngs (2008)
Zhao et al. (2006)
Abrahamson et al. (2013)
Atkinson & Boore (2003)
Zhao et al. (2006)
Atkinson & Boore (2006)
Silva et al (2002)
Pezeshk et al. (2011)
Global Recommendations from GEM GMPE Global Component
Ground Motion Prediction Equations (GMPEs)
Active Shallow Crust
Subduction
Stable Continental
Akkar & Bommer (2010)
Chiou & Youngs (2008)
Zhao et al. (2006)
Abrahamson et al. (2013)
Atkinson & Boore (2003)
Zhao et al. (2006)
Atkinson & Boore (2006)
Silva et al (2002)
Pezeshk et al. (2011)
Global Recommendations from GEM GMPE Global Component
Ground Motion Prediction Equations (GMPEs)
Active Shallow Crust
Subduction
Stable Continental
Akkar & Bommer (2010)
Chiou & Youngs (2008)
Zhao et al. (2006)
Abrahamson et al. (2013)
Atkinson & Boore (2003)
Zhao et al. (2006)
Atkinson & Boore (2006)
Silva et al (2002)
Pezeshk et al. (2011)
Global Recommendations from GEM GMPE Global Component
A Globally Uniform Seismic Hazard Map …
Peak Ground Acceleration (PGA) with a 10 % Probability of Being Exceeded in 50 years
… and model!
Peak Ground Acceleration (PGA) with a 2 % Probability of Being Exceeded in 50 years
… and model!
1‐second Spectral Acceleration with a 10 % Probability of Being Exceeded in 50 years
Where to develop? – Earthquake Catalogues
‣ Assimilate highest quality historical and instrumental catalogues‣ Account for completeness
ISC Reviewed Bulletin (M > 3)
Where to develop? – Subduction Sources
Faulted Earth/USGS Subduction Sources (Wallace et al., 2012)
Where to develop? ‐ Intraplate Regions
‣ Strain cannot resolve; catalogues too short!‣ Active research from the Powell Working Group
Stable Continental Region Polygons (EPRI, 1994)Earthquakes from Schulte & Mooney (2005)
Moving From Global to Regional
‣ Experimental & Provisional
‣ Missing information available at regional scales:‒ Detailed information on fault geology and activity ‒ Time‐dependence ‒ Catalogues with lower completeness magnitudes
‣ To compare global and local, consistency is desirable:‒ Calculation Implementation‒ Testing & Evaluation