GEM's community tools forprobabilistic seismic hazard
modelling and calculation
Marco Pagani, GEM Secretariat, Pavia, IT
Damiano Monelli, GEM Model Facility, SED-ETH, Zürich, CH
Graeme Weatherill, GEM Model Facility, Pavia, IT

Tools for hazard modelling and calculation
Primary Information

Geological information

Historical andinstrumental seismicity

Ground Motion
Prediction Equations

Tectonics related
information

Hazard Modeller's Toolkit(A suite of tools for the processing of basic information and for the preparation ofPSHA Input Models)Seismic Source and Ground Motion Systems(i.e. Seismic Source and Ground Motion Model and corresponding Logic Treestructures)

Hazard module of the OQ-engine

Main goals of GEM’s hazard component
The overall goal of the tools
GEM is to make the PSHA
input model creation andcalculation process fully
reproducible andtransparent.

Instrumental Seismicity catalogue
for Atlantis - version 1.0
Available at
http://atlantis.org/catalogue

Declustering - Method A
STEP 1

Code available at
http://github.org/atlantis
Parameters deﬁned in the report
http://atlantis.org/reportCompleteness - Method B
STEP 2

Code available at
http://github.org/atlantis
Parameters deﬁned in the report
http://atlantis.org/report

Smoothing - Method C
STEP 3

Code available at
http://github.org/atlantis
Parameters deﬁned in the report
http://atlantis.org/report

Gridded seismicity - PSHA input
Available at
http://atlantis.org/input

Main goals of GEM’s hazard component
Promote the creation of transparent,reproducible, open and testable hazard
models- By creating an open repository with PSHA
models coming from different parts of theworld- By working with the local communities on
the completion of new hazard projects- By involving in the activities above theinternational scientific and engineeringcommunity- By offering tools for the preparation ofPSHA input models and for the calculationof hazard

Main features of tools developed‣ Open source projects‒ OQ-engine code is available at the following
repository
http://github.com/gem‒ HMTK code is available at the following
repository
https://github.com/GEMScienceTools/hmtk‣ Coded in python‣ Developed using a unittest approach‣ Everybody can contribute todevelopment under certain rules

Online repository

Hazard Modeller’s Toolkit

The hazard modeller's toolkit
The Hazard Modeler's Toolkit‣ It’s a python library of tools
for processing basic
information and creating
PSHA input models‣ Three main sections:‒ Seismicity‒ Geology‒ Tectonics

https://github.com/GEMScienceTools/hmtk

Example: smoothed seismicity
Tool (Algorithm)

Configurable Settings

Smoothed Seismicity• Kernel choiceFirst implementation based on Frankel(1995) approach:• Bandwidth• Generalised implementation• B-Value• Extended to 3D smoothing• Completeness correction factors now
configurable (can be switched on oroff)• Addition of new Kernels simpler infuture• “Incremental” or “Cumulative” rates• Grid settings• Completeness correction factor• 3D smoothing• Coded but still testing: Isotropic Gaussian (Zechar, 2010),
Adaptive Spherical Fisher Kernel (Kagan & Jackson, 2012)

OQ-engine: introduction

Main features

OQ-engine‣ A hazard and risk calculation engine‣ Organised into a number of libraries (incase, they can be used separately as
more flexible tools for prototyping andresearch)‒ oq-hazardlib‒ oq-risklib‒ oq-nrmllib

Supported architectures and OSs
On your laptop

On your cluster

On clouds accessible through theOpenQuake portal‣ The OQ-engine can run on asingle machine as well as on
a cluster of computers‣ The Operative Systemcurrently supported isUbuntu Linux (support for
additional Operative Systems
might be also available in thefuture)‣ OQ works from thecommand line i.e. no GUI isavailable

A single software for multiple use cases‣ Classical PSHA – used for regional/national scale hazard
assessment as well as in site-specific studies‣ Event-based PSHA– used for the calculation of losses of a
distributed set of assets‣ Scenario hazard – used for urban scale loss analysis‣ Disaggregation (currently only for Classical PSHA) – used for thedefinition of the controlling event/s e.g. for the calculation of
the conditional mean spectrum (Baker, 2011)

Hazard module‣ A summary of the main OQ-engine features:‒ Based on a standardized and flexible input data format‒ Earthquake Rupture Forecast creation for different tectonic regimes(e.g. active shallow crust, stable continental regions, subduction)‒ Calculate hazard considering spatially variable site conditions‒ Stochastic Event Set generation‒ Ground Motion fields calculation (eventually accounting for spatial
correlation of ground motion within-event residuals)‒ Supports logic trees‒ Disaggregation

Documentation‣ OQ-engine manual and OQ-engine risk book are available
http://www.globalquakemodel.org/openquake/support/documentation/

OQ-engine: input data modelInput model‣ An OQ-engine PSHA input model is always described by meansof a logic tree structure‣ The OQ-engine offers a framework, based on the NRML format(XML), to programmatically define logic trees describing
epistemic uncertainties in the source and ground motion
models.
OpenQuake-engine: Structure of the PSHA Input ModelConﬁguration ﬁleSeismic Source Logic Tree

Initial Seismic Source Model A

Ground Motion Logic Tree

Initial Seismic Source Model B...

Modeling Earthquake Sources
Five source typologies:‒ Point Source‒ Area Source

Can be used formodeling distributed
seismicity
With floating ruptures‒ Simple Fault Source‒ Complex Fault Source‒ Characteristic fault Source
Without floating ruptures

Can be used formodeling shallow
crustal faults,
subduction faults

The Point Source
Mmin = 5.0, Mmax = 6.0• Upper Seismogenic
depth• Hypocenter position(lon,lat)• Lower Seismogenic
depth• Nodal Plane (strike, dip, rake) distribution(allowing distribution rates over multiple
rupture orientations/styles)• Hypocenter Depth distribution (allowing
distribution ruptures over depth)• Magnitude Frequency
Distribution• Magnitude Scaling
relationship• Rupture Aspect Ratio

The Point Source
Mmin = 5.0,Mmax = 6.0

Mmin = 5.0,Mmax = 6.5

Ruptures are reshaped as soon
as their width exceed themaximum rupture width(constrained by dip angle andupper and lower seismogenicdepths)- Rupture area is preserved

The Point Source
Examples of rupture sets that can be generated using different
nodal plane distributions
Multiple dip angles

Multiple strike angles

The Point Source
Examples of rupture sets that can be generated using different
nodal plane and hypocentral depth distributions
Multiple strike angles and hypocentral depths

The Area Source

The Simple Fault Source‣ Fault trace‣ Upper seismogenic depth‣ Lower seismogenic depth‣ Dip angle‣‣‣

yRupture size and shape‣

The Complex Fault Source

Sumatra Subduction
Model from SLAB 1.0
Top and bottomedges‣ MagnitudeFrequency
Distribution‣ Magnitude Scaling
Relationship‣ Aspect ratio‣ Rake

The Characteristic Fault Source
The only fault source typesupported in the OQ-engine
without floating ruptures
Parameters:‣ A group of rectangularfault surfaces OR one
simple fault surface OR
one complex faultsurface‣ Magnitude Frequency
Distribution‣ RakeSoftware testingSoftware testing‣ OpenQuake-hazardlib is developed using ‘unit testing’procedures i.e. each function in the software is tested by acorresponding code implementing a number of use cases andaiming at checking correctness
tests/source/complex_fault_test
92
0
100%
tests/source/point_test
280
1
99%
58
tests/source/rupture_test
46
0
100%
tests/source/simple_fault_test
117
0
100%
tests/speedups_test
38
1
97%
59
tests/tom_test
32
0
100%
------------------------------------------------------------------------------TOTAL
8942
388
96%
----------------------------------------------------------------------‣ OpenQuake-hazardlib uses the PEER Tests as ‘Quality Assurance
Tests’
Thomas et al. (2010). Verification of Probabilistic Seismic Hazard Analysis
Computer Programs. Peer report 2010/106.

Software testing: PEER Tests
Vertical Strike-Slip fault with Truncated Gutenberg Richter MFD

Preliminary models implemented

Examples of hazard models implemented‣ United States 2008 (USGS)‣ Canada (Canada Geological Survey)‣ Alaska 2007 (USGS)‣ Japan 2012 (J-SHIS – NIED)‣ SHARE (EU funded project)‣ Australia (Geoscience Australia)‣ South America 2010 (USGS)‣ Mexico (UNAM)‣ Taiwan (Cheng et al., 2007)

OpenQuake

J-SHISOQ-engine hazard
Use examples‣ [fall 2012] verification calculations of the SSHAC level 3 projectsponsored by Eskom (a South African electricity public utility)‣ [winter 2012/2013] calculation of the new generation of hazard
maps in Europe (SHARE project)‣ [spring-summer 2012/2013] calculation of the new generationof hazard maps in the Middle East (EMME project)‣ [fall 2013] calculation of the new generation of hazard maps inCentral Asia (EMCA project)

Stochastic event set and ground motion fields
Total number of sources: 10756
Total number of ruptures: 120832
Gridded Seismicity

2012- Version 2

Stochastic event set and ground motion fields

Thank you
http://globalquakemodel.org