Scrutica
Japan supplies most of the silicon wafers, advanced photoresist, and lithography equipment that DRAM, NAND, and HBM fabs depend on; a major seismic event removes the inputs every advanced-process line needs to keep running — and propagates to the Korean fabs coupled to those same Japanese inputs.
Japan supplies the silicon wafers, semiconductor equipment, and one of the three merchant HBM production lines that AI GPUs cannot ship without — with Micron contributing roughly 21% of global HBM (Q3 2025) from Hiroshima alongside the country's dominant SUMCO / Shin-Etsu wafer supply. A M9 event in the active zone sits within JMA Intensity 6+ of 4 memory fabs; the 2011 Tohoku precedent — a 6-month wafer outage — propagated through every advanced-process supply chain on the planet.
The engine runs the Japan–Korea coupling at full density: it seeds the Japanese semiconductor-input cluster (Shin-Etsu, SUMCO, Tokyo Electron, Advantest, and the rest) and propagates the shock forward through recorded supplier–customer edges, reaching Samsung and the Korean supply chain. What it does notcapture is the input-dependency path to SK Hynix that this page’s fab-level model reasons about but that is not a recorded edge in the substrate, and the seismic-probability and HBM-qualification detail above — the engine run is the propagation skeleton; this analysis is the flesh.