Seismic Hazard (GSHAP PGA, 475-yr return)
This layer maps the level of ground shaking a location can expect from earthquakes.
Category: Physical risks · Mitigating services · Geological Coverage: Global Format: Raster grid (~10 km) Used in risk analysis: Yes — gates Mitigating services
What it shows
This layer maps the level of ground shaking a location can expect from earthquakes. It expresses peak ground acceleration with a 10% chance of being exceeded over 50 years, which corresponds to roughly a 475-year return period. It matters for nature-related risk because strong shaking threatens the stability of buildings, industrial sites and lifeline systems such as transport, energy and water networks.
How it is built
The layer comes from the Global Seismic Hazard Assessment Program (Giardini et al., 1999), which combined regional and national seismic-hazard models into a single harmonised global surface. The measured variable is peak ground acceleration, given as a fraction of the acceleration of gravity. Values reflect the expected intensity of shaking for the chosen probability and exposure period. The product is supplied on an approximately 10 km grid.
How to read it
Higher values indicate areas more exposed to strong ground shaking and therefore greater exposure for infrastructure such as tailings dams, pipelines and storage tanks. Lower values indicate comparatively stable ground. This is a screening surface: it shows where seismic exposure is elevated, not a substitute for a site-specific engineering assessment. The 1999 vintage means it does not reflect more recent local refinements; up-to-date commercial hazard models exist where finer detail is required.
Source
Global Seismic Hazard Assessment Program (GSHAP) — Giardini et al., 1999.
Comparison with the WWF Risk Filter Suite
The WWF Risk Filter Suite has no equivalent indicator. Seismic hazard is a geophysical risk rather than a biodiversity or water risk, and so falls outside the WWF methodology. This is a Darwin extension that broadens physical-hazard screening beyond the WWF set.
Risk analysis
A site is flagged on a dimension by combining a proximity trigger (this layer) with an activity trigger (the entity's ENCORE pressure/service). Proximity only → Potentially material; proximity and the matching ENCORE pressure/service is material → Very material; neither → Not material.
| Dimension | ENCORE service / pressure | Proximity trigger (this layer) | Activity trigger (entity) |
|---|---|---|---|
| Mitigating services | Seismic hazard | Layer value above 0.2 | — |
Legend
Symbolised field: PGA (g, 10% in 50y)
Generated from darwin/layers/layer-seismic-hazard-gshap.toml and risk_indicator_pairs.toml (develop).