Global Seismic Hazard Map

The Global Seismic Hazard Map (version 2023.1) is produced by the Global Earthquake Model
(GEM) Foundation and represents the geographic distribution of Peak Ground Acceleration
(PGA) — the maximum ground shaking intensity — with a 10% probability of being exceeded
in 50 years (475-year return period). Values are computed for reference rock conditions
(shear wave velocity Vs30 of 760–800 m/s) using the most comprehensive global seismological
catalogue and fault data available as of 2023. Compared to the older GSHAP dataset, this
layer incorporates significantly improved source models and ground motion predictions,
making it the preferred choice for modern seismic risk assessment, engineering design,
and insurance exposure modelling.

Technical information

Data coincides with the actual GeoNetwork catalog record - this is our most recent verified data.

Interpreting the data

PGA values are expressed as a fraction of gravitational acceleration
(g), classified from Very Low (0–0.1g) to Extreme (> 0.9g). Higher values indicate areas
where the ground is expected to shake more violently during rare but plausible earthquake
events. Areas exceeding 0.5g correspond to zones of very high seismic hazard typically
associated with major active faults or subduction zones.
[colour ramp to be confirmed]

Resolution and update frequency

0.1° × 0.1° (~10 km at the equator), reprojected to EPSG:3857.
Version 2023.1 is the current release; GEM periodically updates the model as new data
becomes available.

Source

https://www.globalquakemodel.org/product/global-seismic-hazard-map (GEM Foundation — Global Seismic Hazard Map 2023.1). Licensed under CC BY-SA 4.0 / CC BY-NC-SA 4.0. Commercial use requires a tailored licence agreement with the GEM Foundation.