Seismic screening and live monitoring.

The shaking comes from the ground-motion models of NRCan’s national hazard model, combined as NRCan combined them for its published BC earthquake scenarios. They turn magnitude, depth, fault type and distance into peak ground acceleration and spectral acceleration at 0.3, 0.6 and 1.0 seconds — the periods NRCan’s damage curves use — at the coordinates of each of your buildings, not averaged over a region.

Each building is read against the Canadian damage curves NRCan published with its national seismic risk model, at the design level NRCan assigns from the building’s era and seismic zone. Colours begin where those curves give an even chance of slight, moderate or extensive damage, read at the shaking × 1.046 — a small inspection margin, stated on every result. Tested held-out against NRCan’s own building-by-building damage for four large BC scenarios, it flags about 95 % of the buildings NRCan puts at moderate damage or worse as Orange or Red — pooled, on par with NRCan’s own median shaking; weakest right beside a crustal fault.

A large earthquake is not a point. Once rupture size starts to matter, the event is modelled as a rupture surface — on NRCan’s fault geometry where the earthquake lies on a known fault — and every building is measured to the nearest point of that surface. On a Cascadia run that is the difference between a comfortable number and a real one.

Live feeds from Natural Resources Canada and the United States Geological Survey, watched together. A Puget Sound earthquake shakes Victoria, so the border is not a filter.

Historic and deterministic scenario runs come from NRCan’s published earthquake scenario catalogue and Canada’s OpenDRR datasets. “The Big One” on your map is a documented rupture, not a magnitude we picked. Past earthquakes are re-run from their recorded location and magnitude, with the USGS’s measured shaking shown alongside where it exists.

The same earthquake does not arrive the same everywhere. Bedrock passes the shaking through; soft soil traps and amplifies it — on the softest ground a building can often shake two to four times harder than an identical building on rock a kilometre away. Ground type is one of the five things you enter, and it is applied to every result the NBC 2020 way: a known class is read at the most amplifying ground in its range, unknown ground as Class D with the C–E range it could be, and the ground-motion models apply their own site response at every period — which is why a facility can read above the shaking band drawn around it on the map.

A seismically resilient building built in 1999 is not the same as a seismically resilient building built in 2023 — codes change, and the ground-motion research underneath them changes too. FacilityShake accounts for both: every building is screened against the code era it was actually built under and the seismic zone it stands in, the way NRCan’s national risk model does it, from pre-code stock to modern code — not a generic average. And where a professional engineer has already assessed a building, you enter their numbers and the tool carries them from there.