What-if impact desks · education
Scenario briefs
Hypothetical impact desks grounded in USGS-style ShakeMap concepts, MMI language, and plain-English risk themes. These pages explore what if — they do not predict when or where a quake will happen.
Inland · Midcontinent
St. Louis / New Madrid — hypothetical M8
What-if desk for a great New Madrid Seismic Zone rupture: strong-shake language for St. Louis metro and Mid-South / Midwest river cities. No tsunami (inland).
Open impact desk → Coastal · Cascadia → NorCalSan Francisco Bay — Cascadia M9 what-if
Hypothetical M9 on the Cascadia subduction zone and how Northern California, including the Bay Area, could experience shake and coastal tsunami effects under clear assumptions.
Open impact desk →
Framing draws on USGS educational materials for the New Madrid Seismic Zone, Cascadia, ShakeMap / MMI concepts, and official tsunami guidance at
usgs.gov and
tsunami.gov.
Ring of Fire does not replace those sources.