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Seismic Intensity Estimates
Moving past a single magnitude number to site-specific seismic intensities — what the shaking was actually like where people were, which is what you need to make decisions after it stops.
For significant USGS western U.S. earthquakes we report observed intensities at seismic stations and ShakeMap-interpolated intensities at named places.
Our vision →Recent seismic activity
11 events in the 30 days to 2026-09-17T12:31:37.057000Z · intensity reported for 10 of them.
Circle size is magnitude; fill is the highest intensity estimated at any populated place. Grey means no intensity report yet.
- M4.2 10 km 37 km ENE of Nelson, Canada 2026-09-17T12:31:37.057000Z —
- M3.7 20 km 24 km W of Petrolia, CA 2026-09-16T14:34:51.940000Z Weak(II)
- M4.1 7 km 20 km WSW of Gerlach, Nevada 2026-09-16T07:17:25.899000Z Not felt(I)
- M3.7 19 km 26 km W of Petrolia, CA 2026-09-10T01:24:47.490000Z Weak(II)
- M3.7 20 km 24 km W of Petrolia, CA 2026-09-10T01:24:03.810000Z Weak(II)
- M3.7 24 km 35 km E of Hydesville, CA 2026-09-07T21:44:24.910000Z Weak(II)
Showing 6 of 11. See the rest →
About Seismic Intensities
Strong ground motions are rare and outside of most people's experiences. Our goal is to develop compelling media that communicates site-specific seismic intensity as post-earthquake science content that is accurate, visual, and shareable — helping people understand intensity in terms they can see and feel. These are the formats we produce today. We are still building.
Available now
Six formats, produced automatically after a significant eventPopulation MMI List
Estimated intensity at every populated place the ShakeMap grid covers — who felt what, by name.
See the list → Event summarySeismic Station MMI List
Intensity derived directly from station recordings — measured ground motion, not interpolated.
See the list → Site reportNearest Population Site Report
One place in depth: interpolated MMI, four NGA-West2 model estimates, site Vs30, and peak ground motion.
Read the report → Video · BBP motionNearest Population Site Video
Everyday objects shaken by a physics-based seismogram computed on the SCEC Broadband Platform for the closest town.
Watch → Video · FDSN motionNearest Seismic Station Video
The same scene driven by a real recording — an FDSN waveform with instrument response removed and integrated to displacement.
Watch → Video · BBP motionGround Motion Decay Video
One earthquake at 5, 50, and 100 km side by side, showing how quickly the shaking people feel falls off with distance.
Watch →Site last deployed: September 21, 2026.