How does the richter scale increase




















Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many people do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibration similar to the passing of a truck. Duration estimated. Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably.

Felt by nearly everyone; many awakened. Unstable objects overturned. Pendulum clocks may stop. Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken.

Damage slight in specially designed structures; considerable damage in ordinary substantial buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls.

Heavy furniture overturned. Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations. Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations.

Rail bent. Few, if any masonry structures remain standing. Bridges destroyed. Rails bent greatly. Damage total. Lines of sight and level are distorted.

Objects thrown into the air. Another measure of the relative strength of an earthquake is the size of the area over which the shaking is noticed. This measure has been particularly useful in estimating the relative severity of historic shocks that were not recorded by seismographs or did not occur in populated areas. The extent of the associated felt areas indicates that some comparatively large earthquakes have occurred in the past in places not considered by the general public to be regions of major earthquake activity.

In the right conditions, the violent shaking from an earthquake will make loosely packed sediments and soil behave like a liquid. When a building or house is built on this type of sediment, liquefaction will cause the structure to collapse more easily. Highly developed areas built on loose ground material can suffer severe damage from even a relatively mild earthquake.

Liquefaction can also cause severe mudslides. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Prev NEXT. Forces of Nature.

Natural Disasters. Cite This! It's a "logarithmic" scale, which means that each one-point increase on the scale represents a fold increase in the magnitude of the quake. The energy released by an earthquake increases at an even steeper rate, going up by a factor of 32 for each one-point increase in magnitude.

Therefore, a quake with magnitude between 2 and 3 is the lowest normally perceptible to humans. A magnitude 5 quake is considered moderate.



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