GCAD-Global v1.2 and V9 analysis package: occurrence, detection and the global dark figure of industrial chemical accidents (1970-2025)

Harmonised multi-source corpus of 525,632 chemical-accident records (ARIA/BARPI France; NRC/USCG USA; eMARS EU; GDELT; MEM-CN; DesInventar third channel) with severity tiering, cross-source entity resolution, detection/dark-figure analysis tables (T1-T27), main figures (V9 Fig1-Fig5), extended data figures and extended data tables (EDT1-4), full Python pipeline (scripts 10-113), satellite benchmark results (NASA GIBS, six satellite-era catastrophes), and the V9 manuscript and cover letter.