The OpenQuake Engine is GEM ’s state-of-the-art software for seismic hazard and risk assessment at varying scales of resolution, from global to local. It can be used on a cluster, in the cloud or on a laptop. It is open-source, fully transparent and can be used with GEM or user-developed models to carry out scenario-based and probabilistic calculations and produce a great variety of outputs.

Development Philosophy

Our work is guided by some core values that allow us to play as a trustable partner providing knowledge, data and resources for earthquake risk assessment worldwide.
We strongly believe that our development philosophy should be based on the following two key principles:  


  • It is a free, truly open-source developed, accessible software for (earthquake) hazard and risk modelling
  • Supported by documentation and technical support

Test-Driven Development Environment

Ensures a higher quality of product that should be robust and should meet the users-requirements

Rich Feature Set

  • large set of source typologies for modelling faults as well as distributed seismicity
  • explicit representation of uncertainty, including separation of epistemic from aleatory
  • logic tree support (representing epistemic uncertainty)
  • calculates ground motion fields taking into account the spatial correlation of ground motion residuals
  • accounts for spatially variable site conditions
  • insured loss extension (based on simple limits and deductibles)
  • benefit-cost ratio extension
  • supported asset typologies: structure/non-structural components/contents/occupants
  • vulnerability uncertainty correlation
  • risk calculators can run with precomputed hazard curves and ground motion fields



Hazard calculators & outputs

Classical Probabilistic Seismic Hazard Assessment (PSHA)

  • hazard curves,
  • hazard maps,
  • uniform hazard spectra (UHS )
  • disaggregation

Event-based hazard

  • stochastic earthquake event sets
  • ground motion fields
  • hazard curves
  • hazard maps

Scenario hazard

  • single event - stochastically generated ground motion fields

Physical risk calculators & outputs

Classical PSHA-based risk

  • asset-specific loss exceedance curves
  • average annual loss
  • loss maps
  • building typology disaggregation

Event-based risk

  • event loss tables,
  • loss exceedance curves - asset specific and aggregated
  • average annual loss
  • loss maps
  • loss disaggregation

Scenario risk

  • loss statistics
  • loss maps

Scenario damage

  • collapse maps
  • damage distribution per asset and building typology