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Intensity Lab

Modified Mercalli Intensity VI MMI VI: Strong shaking

MMI six (VI) is strong shaking. Felt by all; many frightened. Some run outdoors. Walking feels unsteady. Damage slight. Typical peak ground acceleration is 9.2–18% of gravity, and the damage potential is light.

What MMI VI does

Perceived shaking
Strong
Damage potential
Light
Peak acceleration
9.2–18% g
Peak velocity
16–31 cm/s

What people feel

  • Felt by everyone; many frightened
  • Many run outdoors
  • Walking feels unsteady
  • Some difficulty standing

What objects do

  • Windows and dishes fall and break
  • Books and objects fall from shelves
  • Small bells ring loudly
  • Heavy furniture moved or overturned

What happens to buildings

  • Plaster falls from walls and ceilings
  • Chimneys crack
  • Trees shaken slightly to moderately
  • Slight damage to ordinary buildings

Also at this level, in other versions of the scale

Sources: the USGS Modified Mercalli Intensity scale (Wood and Neumann, 1931; Richter, 1958); ground-motion ranges from the USGS ShakeMap documentation (Worden et al., 2012), approximate and overlapping between neighbouring levels. See instrumental intensity. An older example: MMI six (VI) on YouTube.

Seen on camera: 21 clips rated MMI VI

Each clip is rated from the effects it shows. A rating describes one camera at one place, not a whole town.

All clips at VI →
VI Outdoor lap pool during earthquake. M7.7 10 km WSW of Pitaloza Arriba, Panama · Catalina Cabins, Santa Catalina, Veraguas, Panama · 0:41 Seen: water in containers or pools sloshes strongly. Setting: Pools, Trees VI Students in classroom during earthquake M7.7 10 km WSW of Pitaloza Arriba, Panama · Chitré, Herrera, Panama (school) · 1:05 Seen: many frightened; many run for shelter or outdoors. Setting: Public spaces VI Crowd exiting shopping mall M7.7 10 km WSW of Pitaloza Arriba, Panama · 0:08 Seen: many frightened; many run for shelter or outdoors. Setting: Stores VI Interior of shopping mall M7.7 10 km WSW of Pitaloza Arriba, Panama · 0:22 Seen: walking unsteady; some difficulty standing. Setting: Stores VI Interior of drug store in Willits M5.6 11 km N of Redwood Valley, CA · 0:29 Seen: goods, dishes or books fall from shelves. Setting: Stores VI Interior of retail shopping store. M5.6 11 km N of Redwood Valley, CA · 0:33 Seen: goods, dishes or books fall from shelves. Setting: Stores VI Store shelves during shaking M5.6 11 km N of Redwood Valley, CA · Willits, CA · 0:07 Seen: goods, dishes or books fall from shelves. Setting: Stores VI Store shelves during shaking M5.6 11 km N of Redwood Valley, CA · Willits, CA · 0:05 Seen: goods, dishes or books fall from shelves. Setting: Stores VI Interior and exterior cameras at a single family home during winter. M6.4 15km WSW of Ferndale, CA · Ferndale, CA · 0:28 Seen: many frightened; many run for shelter or outdoors. Setting: Trees, Vehicles, Homes VI Water shaking out of backyard above ground pool M7.1 Ridgecrest Earthquake Sequence · Ridgecrest, California · 0:34 Seen: water in containers or pools sloshes strongly. Setting: Pools, Homes VI Interior of gas station market. M6.4 Ridgecrest Earthquake Sequence · 0:22 Seen: goods, dishes or books fall from shelves. Setting: Stores VI Interior restaurant M6.4 Ridgecrest Earthquake Sequence · Ridgecrest, CA · 0:08 Seen: heavy furniture moves. Setting: Public spaces

See all 21 clips →

Simulated at MMI VI

Our animations of named places where the estimated shaking reached this level, driven by simulated or recorded ground motion.

How the animations work →
VI Kitchen: Barra Winery, Redwood Valley, CA M5.6 11 km N of Redwood Valley, CA VI Tabletop: Barra Winery, Redwood Valley, CA M5.6 11 km N of Redwood Valley, CA

Recently at MMI VI in our region

Earthquakes in the western United States and northern Mexico whose strongest shaking at a named place reached this level.

Recent earthquakes →

How MMI VI is estimated

From instruments

USGS ShakeMap converts peak ground acceleration and velocity recorded at seismic stations into intensity. About 9.2–18% g of acceleration corresponds to MMI six (VI).

From people's reports

USGS Did You Feel It? turns answers from thousands of people into a community intensity for each place. If you felt an earthquake, report it there.

From footage

We rate each clip with questions built from the scale's own statements: what people, objects and buildings do on camera. A rating describes one camera at one place.

Common questions

What magnitude causes MMI VI?

It depends on distance and ground conditions, not magnitude alone. In our region, MMI six (VI) has come from earthquakes such as M4.7 near Brawley, CA (2026); M5.7 near Silver Springs, Nevada (2026).

What does MMI VI feel like?

Felt by everyone; many frightened. Many run outdoors. Walking feels unsteady. Some difficulty standing.

How strong is the ground motion at MMI VI?

Peak ground acceleration is typically 9.2–18% g and peak velocity 16–31 cm/s.

How is intensity different from magnitude?

Magnitude measures the energy an earthquake releases and is one number per earthquake. Intensity describes the shaking at one place, so a single earthquake produces many intensities, strongest near the fault and weaker with distance.