Tokyo Earthquake: Memory Fab Exposure

Scenario · Seismic exposure

Seismic exposure modeling for the semiconductor supply chain, assessing Japan's concentration of silicon wafer production, NAND/DRAM fabrication, and specialized SME against historical and projected fault ruptures.

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.

Supply Chain Exposure Analysis

8 Japan fabs, 5 Korea fabs, 4 in scenario zone. HBM concentration (Q3 2025): SK Hynix ~57%, Samsung ~22%, Micron ~21%. HERP probability estimates with fab-level geographic exposure. Active: Nankai Trough megathrust (M8-9 class, modeled at M9.0)Three seismic scenarios mapped against the fabs that produce DRAM, NAND, and HBM memory for AI GPUs. A single event at any of three locations disrupts the entire AI GPU memory supply chain. Active: Nankai Trough megathrust (M8-9 class, modeled at M9.0)

Choose scenario

Magnitude · Severity

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.

Methodology →HERP long-term seismic hazard · Counterpoint Research HBM share + Omdia wafer share · USGS catalog

Active scenarioNankai Trough megathrust (M8-9 class, modeled at M9.0)

Concentration AnalysisHHI + Japan-exposure for DRAM, NAND, HBM, silicon wafers, and equipment markets, plus the fabs in the active scenario zone.4 fabs in scenario zone

Compound ScenariosKorea / Japan / Taiwan multi-country couplings the cascade engine doesn't natively combine — empirical stress on the broader memory chain.3 multi-country

Market ImpactHistorical fab outages (2011 Tohoku, 2016 Kumamoto, etc.) with per-product price impact, recovery time, and market response.4 historical events

Scenario DetailsReference cards for each seismic scenario — magnitude, HERP 30-yr probability, affected fab list, calibration anchor.3 scenarios

MethodologyHERP probability inputs, severity formula (4 weighted factors), per-fab GPU-SKU inference, and source authority tiering.