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Intensity Lab

Seismic intensity

Magnitude is one number. Intensity is what happened where you were.

An earthquake has one magnitude but a different intensity at every place it shakes. The Modified Mercalli scale, from I to X, describes what that shaking does to people, objects and buildings. See each level in real footage, and see how hard recent earthquakes shook 2,002 named places in the western United States and northern Mexico.

Explore the scale Watch shaking videos
MMI VII Clip of the day
Exterior home and yard, M5.6 11 km N of Redwood Valley, CA. Rated MMI VII from the effects it shows. What MMI VII means

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One earthquake, many intensities

The 2019 M7.1 Ridgecrest earthquake had one magnitude. At the named places it reached, intensity ran from VII near the fault to IV in Los Angeles.

The Ridgecrest event page →
Intensity at named places against distance from the epicentre: Ridgecrest, 18 km, MMI VII; Weldon, 63 km, MMI V; Mojave, 95 km, MMI V; Lancaster, 129 km, MMI IV; Adelanto, 133 km, MMI V; Lucerne Valley, 158 km, MMI V; Los Angeles, 200 km, MMI IV IV V VI VII 0 50 100 150 200 Distance from epicentre (km) Ridgecrest 18 km Weldon 63 km Mojave 95 km Lancaster 129 km Adelanto 133 km Lucerne Valley 158 km Los Angeles 200 km
ShakeMap intensity at named places, by distance from the epicentre. Intensity falls with distance, but not evenly: local ground conditions matter too.

Recorded and simulated, same earthquake

A camera in Ridgecrest, and our animation of the ground motion simulated there.

VII Recorded: Driveway with two vehicles and pedestrian VII Simulated: Ridgecrest, Kitchen scene

Play them side by side →

The shaking video collection

Camera footage from earthquakes around the world. We rate each clip by answering questions built from the scale's own statements: what people, objects and buildings do on camera.

Browse all clips →
  • 38rated clips
  • 11earthquakes
  • 6countries
  • V–Xlevels shown so far
V MMI V: Moderate Trees and bushes shaken slightly. 7 clips rated V VI MMI VI: Strong Goods, dishes or books fall from shelves. 18 clips rated VI VII MMI VII: Very Strong Trees and bushes shaken moderately to strongly. 7 clips rated VII VIII MMI VIII: Severe Heavy furniture overturned and displaced. 4 clips rated VIII X MMI X: Extreme Most masonry and frame buildings collapse. 2 clips rated X

Latest earthquake in our region

Recent earthquakes →
M4.0 10 km N of Lake Pillsbury, CA 2026-10-28T12:01:11.470000Z · Strongest shaking at named places: IIRedwood ValleyIIUpper LakeIIWillits Shaking by town →

Intensity at named places is interpolated from the USGS ShakeMap. 8 earthquakes of magnitude 3.5 or more in the latest 30 days of our records.

Explore further

Recorded vs. simulated Real footage beside our simulation of the same earthquake at the same place. How we simulate shaking Ground motion from physics-based simulations, drawn as Kitchen and Tabletop scenes. Shaking fades with distance One earthquake at 5, 50 and 100 km from the epicentre, side by side. Coverage and the API 2,002 named places from northern Mexico to Washington, and an API for developers.

Site last deployed: November 2, 2026.