Seismic Intensity : Nine (IX) - Destructive

Nine (IX) : General panic. Damage slight to moderate (possibly heavy) in well-designed structures. Well-designed structures thrown out of plumb. Damage moderate to great in substantial buildings, with a possible partial collapse. Some buildings may be shifted off foundations. Walls can fall down or collapse.

Perceived Shaking


Potential Damage


Peak Ground Motion Acceleration

65 to 124 (%g)

Peak Ground Motion Velocity

60 to 116 (cm/sec)

Video Example

Intensity Nine (IX)

Reference: Modified Mercalli Intensity Scale (Adapted from Sieberg's Mercalli—Cancani scale, modified and condensed)