2015/9/16 Modified Mercalli Intensity(MMI) In他raep的av间wndc 亚dsSn品 ys broken.N IX violent a5ms nship between earthqu Magnitude 10-30 40-49 0-m 4.0-4.9 IV-V 50-59 vi-vI 60-69 vI-vm 70+2015/9/16 8 Ⅰ Instrumental. Not felt except by a very few under especially favorable circumstances. Ⅱ Weak. Felt only by a few persons at rest, especially on upper floors of buildings. Delicately suspended objects may swing. Ⅲ Slight. Felt quite noticeably indoors, especially on upper floors or buildings, but many people do not recognize it as an earthquake. Ⅳ Moderate. During the day felt indoors by many, outdoors by few. At night some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably. Modified Mercalli Intensity (MMI) 2015/9/16 Haibei XIONG College of Civil Engineering, Tongji University 43 Ⅴ Rather Strong. Felt by nearly everyone, many awakened. Some dishes, windows, etc., broken; a few instances of cracked plaster; unstable objects overturned. Disturbances of trees, poles, and other tall objects sometimes noticed. Ⅵ Strong. Felt by all, many frightened and run outdoors. Some heavy furniture moved; a few instances of fallen plaster or damaged chimneys. Damage slight. Ⅶ Very Strong Everybody runs outdoors. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable in poorly built or badly designed structures; some chimneys broken. Noticed by persons driving motor cars. 2015/9/16 Haibei XIONG College of Civil Engineering, Tongji University 44 Ⅸ Violent Damage considerable in specially designed structures; well designed frame structures thrown out of plumb; great in substantial buildings, with partial collapse. Buildings shifted off foundations. Ground cracked conspicuously. Underground pipes broken. Ⅷ Destructive. Damage slight in specially designed structures; considerable in ordinary substantial buildings, with partial collapse; great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, and walls. Heavy furniture overturned. Sand and mud ejected in small amounts. Changes in well water. Persons driving motor cars disturbed. 2015/9/16 Haibei XIONG College of Civil Engineering, Tongji University 45 Ⅺ Extreme. Few, if any, masonry structures remain standing. Bridges destroyed. Numerous landslides, cracks and deformation of the ground. Ⅻ Catastrophic Total destruction – Everything is destroyed. Lines of sight and level distorted. Objects thrown into the air. The ground moves in waves or ripples. Large amounts of rock move position. Landscape altered, or levelled by several meters. In some cases, even the routes of rivers are changed. ⅩIntense Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations; ground badly cracked. Rails bent. Landslide, Water splashed (slopped) over banks. 2015/9/16 Haibei XIONG College of Civil Engineering, Tongji University 46 Q5 What is the relationship between earthquake Magnitude and Intensity? Magnitude Typical Maximum MMI 1.0 – 3.0 I 4.0 – 4.9 II – III 4.0 – 4.9 IV –V 5.0 – 5.9 VI –VII 6.0 – 6.9 VII –VIII 7.0+ IX or higher 2015/9/16 Haibei XIONG College of Civil Engineering, Tongji University 47 Q6: According to MMI scale, could you give us an evaluation of earthquake intensities of Dujiangyan and Shanghai coursed by Wenchuan Earthquake (2008.5.12). Date May 12, 2008) Magnitude 7.98 Ms [1]/7.9 Mw [2] Depth 19 kilometres (12 mi) Epicenter 31°01′16″N 103°22′01″ E31.021°N 103.367°E (Yingxiu, Wenchuan, in Sichuan Province) Max. intensity XI MM/CSIS[3][4] Casualties 69,195 dead[6] 18,392 missing[6][7] 2015/9/16 Haibei XIONG College of Civil Engineering, Tongji University 48