International collaboration within thehazard component of the Global
Earthquake Model
Marco Pagani1 | Damiano Monelli2 | Graeme Weatherill3
1 GEM Secretariat, Pavia, Italy
2 GEM Model Facility @ ETH Zurich, Switzerland
3 GEM Model Facility @ GEM Secretariat, Pavia, Italy

Presentation outline‣ Possible ways for establishing international scientificcollaboration in seismic hazard‣ Some examples from the GEM experience“Although scientific practice still invokes images of the ‘lone,
long-haired genius, mouldering in an attic or basement
workshop…motivated by the flame burning within him’ (Price,1963, p. 3), scientific knowledge creation is increasinglydependent on collaborative efforts”
Hoekman et al. (2009)

GEM a global collaborative effort“A collaborative effort devised and launched by OECD’s Global
Science Forum, aimed at engaging the global community in thetransparent design, development and deployment of uniform
open standards and tools for earthquake risk assessment
worldwide”‣ Combining the strengths, knowledge and needs of public and private sectors‣ Currently 10 corporates, 15 nations or national organizations,
8 international organizations

GEM a global collaborative effort
Global projects aiming at
the definition of standard
for collecting, processing
and storing information
Regional, independent
projects targeted at thecreation of hazard and risk
modelsCollaboration schemes
Possible alternatives:‣ Creation of harmonised
databases (e.g. federated
seismic networks, fault
databases)‣ Development of new
methodologies and/or tools(e.g. methods for integrating
crustal deformation intoPSHA)‣ Design and implementationof PSHA models (e.g.
development of aharmonised hazard models)Collaboration needs
Main preconditions:‣ Talk the same language. From a scientific point of view thismeans:‒ Contribute to standards for representing the basic information‒ Share methods and tools for model building and hazard calculation‣ Discuss openly!

Global Components

Global Instrumental Earthquake Catalogue
What is it?
‣ A global catalogue of earthquakes containing about 25.000
events occurred in the period between AD 1900 and 2009.
‒ In the interval 1900-1917 the catalogue comprises events withmagnitude greater or equal to 7.5;
‒ from 1918 until 1959 it has events with magnitude greater of equal to6.25 and,‒ from 1960 on the catalogue includes earthquakes with magnitude
equal or greater than 5.5.

Global Instrumental Earthquake Catalogue
What are the special features:‣ This catalogue is composed of earthquakes with homogeneous
locations and magnitude estimates, determined using thesame tools and techniques to the extent possible.
‣ The magnitude determination and location procedures applied
represent a synthesis of state-of-the art methods.
‣ Each event has a MW value (with related uncertainty) based onseismic moment where possible (mainly for events that
occurred between 1976-2009) and where not, empirical
relations between MW and MS/mb are used to obtain proxyvalues of moment magnitude.

Global Instrumental Earthquake Catalogue
What are the special features:‣ The majority of events in the pre-1971 period have their MS
magnitudes computed systematically from the surface wave
amplitude measurements recovered from the historical paperbased seismic station bulletins.
‣ These MS magnitudes were never available before and are theresult of a massive data entry effort carried out within thescope of this project.

Global Instrumental Earthquake Catalogue
In Centennial Catalogue, magnitudes have been
compiled from different authors and scales
Rothe MS
Pasadena
Abe mB

G&R

In GEM Catalogue, magnitudes have been
recomputed from original amplitudes and periods
and then, where necessary, converted to Mw.
Mw (literature)

OthersAbe MS

Mw (GEM mb)

ISC MSGCMT Mw

P&S Mw

Mw GCMTNEIC MS

Mw (GEM MS)

ISC mbUncertainties and quality of magnitude
determinations is given in GEM Catalogue

Development of new
methodologies and/or tools

OpenQuake Hazard Tools‣ Openquake-hazard: a module in the OpenQuake-engine
dedicated to Seismic Hazard Analysis (Openquake-engine is an
open source project of the Global Earthquake Model)‣ Openquake-modeller: a suite of tools for PSHA input model
preparation e.g. catalogue processing, seismicity recurrence
calculation

Open Source code. Available at the following
address:
http://github.com/gem

OpenQuake Hazard Tools

OpenQuake Hazard‣ The main functionalities of OpenQuakeengine are:
‒ Earthquake Rupture Forecast creation fordifferent tectonic regimes (e.g. activeshallow crust, stable continental regions,subduction)‒ Calculate hazard considering spatiallyvariable site conditions‒ Stochastic Event Set generation‒ Ground Motion fields calculation(eventually accounting for spatialcorrelation)‒ Supports logic trees‒ Seismic hazard disaggregation

OpenQuake Hazard Tools‣ OpenQuake-engine used for calculation in most of thecurrently active regional programmes: SHARE, EMME andEMCA‣ Training workshops (completed and planned) in Sub-SaharanAfrica, Central Asia, Balkan Region, South East Asia (Brisbaneand Philippines), South Asia
‣ OpenQuake-modeller and OpenQuake-engine are currently ina phase of extensive refactoring that will hopefully generate
more powerful and flexible tools

Regional Programmes

Hazard Regional Programmes… several new
initiatives currently
starting and/ordeveloping

The role of Hazard Regional Programmes‣ Create regional datasets e.g. EQ catalogues (historic andinstrumental) – active faults – seismic sources – GMPEs – siteeffects‣ Collaborate with GEM on producing and validating consensual
methodologies + computational infrastructure for seismic
hazard and risk calculations‣ Evaluate the results of GEM’s global components‣ Ensure GEM standards and procedures are compatible withregional conditions‣ Create harmonized seismic hazard and risk models acrossborders

The SHARE example‣ 18 international partners involved‣ Numerous new databases developed at regional scale:historical and instrumental seismicity DBs, active faults DB‣ Harmonised PSHA input models:‒ Area source based model‒ Fault + background seismicity model‒ 2 Smoothed seismicity models

The SHARE example

The SHARE example‣ Calculations performed with OpenQuake: feedback of greatsignificance provided to the GEM model facility for further
improving the capabilities of the engine

Conclusions‣ International collaboration is A CORE activity within the Global
Earthquake Model‣ Different ways are available to pursue GEM’s goals whileinternational collaboration remains central‣ Several GEM’s regional initiatives now active or in the processof starting soon … it’s time to join, we need your contribution