Global Seismic Hazard Map

The Global Earthquake Model (GEM) Global Seismic Hazard Map (version 2026.1) is the first probabilistic seismic hazard map to depict seismic hazard globally, including the oceans. This map replaces the previous version (v2023.1) released in June 2023. The main map depicts the geographic distribution of the Peak Ground Acceleration (PGA) with a 10% probability of being exceeded in 50 years, computed for reference rock conditions (shear wave velocity, VS,30 of 800 m/s). The map was created by collating maps computed using national and regional probabilistic seismic hazard models developed by various institutions and projects, in collaboration with GEM Foundation scientists. The OpenQuake Engine, an open-source seismic hazard and risk calculation software developed principally by the GEM Foundation, was used to calculate the hazard values. The map is based on a database of hazard models described using the OpenQuake engine data format (NRML); those models implemented initially in other software formats were converted into NRML. While translating these models, various checks were performed to test the compatibility between the original and new results computed using the OpenQuake Engine. Due to possible model limitations, regions portrayed with low hazard may still experience potentially damaging earthquakes. Technical details on the compilation of the hazard maps and the underlying models - including updates to model components made by GEM - are available at https://hazard.openquake.org/