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MODIFIED MERCALLI INTENSITY (MMI) SCALE INTENSITY DESCRIPTION I Not felt except by a very few under especially favorable circumstances. II Felt only by a few persons at rest, especially on upper floors of buildings. Delicately suspended objects may swing. Felt quite noticeably indoors, especially on upper floors of buildings, but many III people do not recognize it as an earthquake. Standing autos may rock slightly. Vibration like passing of a truck. During the day felt indoors by many, outdoors by few. At night, some awakened. IV Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing autos rock noticeably. Felt by nearly everyone; many awakened. Some dishes, windows, etc. broken; a V few instances of cracked plaster; unstable objects overturned. Disturbance of trees, poles and other tall objects noticed. Pendulum clocks may stop. VI Felt by all; many frightened and run outdoors. Some heavy furniture moved; a few instances of fallen plaster or damaged chimneys. Damage slight. Everybody runs outdoors. Damage negligible in buildings of good design and VII construction; slight to moderate in well-built ordinary structures; considerable in poorly built or badly designed structures; some chimneys broken. Noticed by persons driving autos. Damage slight in specially designed structures; considerable in ordinary substantial buildings with partial collapse; great in poorly built structures. Panel VIII walls thrown out of frame structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned. Sand and mud ejected in small amounts. Changes in well water. Disturbs persons driving autos. Damage considerable in specially designed structures; well designed frame IX structures thrown out of plumb; great in substantial buildings, with partial collapse. Buildings shifted off of foundations. Ground cracks conspicuously. Underground pipes broken. Some well-built wooden structures destroyed; most masonry and frame structures X destroyed with foundations; ground badly cracked. Rails bent. Landslides considerable from riverbanks and steep slopes. Shifted sand and mud. Water sloshes over banks. Few, if any, masonry structures remain standing. Bridges destroyed. Broad XI fissures in ground. Underground pipe lines completely out of service. Earth slumps and land slips in soft ground. Rails bent greatly. XII Damage total. Waves seen on ground surface. Lines of sight and level distorted. Objects thrown up in air.