EQK · Physics
Earthquake
GEM PGA × Vs30 site amplification · v1.0 · 2026-04
San Francisco Bay to Salinas — high-PGA corridor along the San Andreas
Site-amplified PGA on a 90 m grid. The Surfaces score is derived from the 475-year GEM PGA modulated by local Vs30 amplification.
What ships
Surfaces — 0–1 susceptibility derived from the 475-year GEM PGA modulated by Vs30 amplification.
Every release: 0–1 score · 5-class band · per-pixel uncertainty · input-coverage mask · STAC item · methodology doc.
Inputs
GEM 2023 seismic hazard, USGS Vs30, soil-class amplification factors