Comparison of Instrumental and Felt Intensity
Peak ground acceleration provides a measurement of instrumental intensity, that is, ground shaking recorded by seismic instruments. Other intensity scales measure felt intensity, based on eyewitness reports, felt shaking, and observed damage. There is correlation between these scales, but not always absolute agreement since experiences and damage can be affected by many other factors, including the quality of earthquake engineering.
Generally speaking,
- 0.001 g (0.01 m/s²) – perceptible by people
- 0.02 g (0.2 m/s²) – people lose their balance
- 0.50 g – very high; well-designed buildings can survive if the duration is short.
Read more about this topic: Peak Ground Acceleration
Famous quotes containing the words comparison of, comparison, instrumental, felt and/or intensity:
“We teach boys to be such men as we are. We do not teach them to aspire to be all they can. We do not give them a training as if we believed in their noble nature. We scarce educate their bodies. We do not train the eye and the hand. We exercise their understandings to the apprehension and comparison of some facts, to a skill in numbers, in words; we aim to make accountants, attorneys, engineers; but not to make able, earnest, great- hearted men.”
—Ralph Waldo Emerson (1803–1882)
“We teach boys to be such men as we are. We do not teach them to aspire to be all they can. We do not give them a training as if we believed in their noble nature. We scarce educate their bodies. We do not train the eye and the hand. We exercise their understandings to the apprehension and comparison of some facts, to a skill in numbers, in words; we aim to make accountants, attorneys, engineers; but not to make able, earnest, great- hearted men.”
—Ralph Waldo Emerson (1803–1882)
“All history attests that man has subjected woman to his will, used her as a means to promote his selfish gratification, to minister to his sensual pleasures, to be instrumental in promoting his comfort; but never has he desired to elevate her to that rank she was created to fill. He has done all he could to debase and enslave her mind; and now he looks triumphantly on the ruin he has wrought, and say, the being he has thus deeply injured is his inferior.”
—Sarah M. Grimke (1792–1873)
“I felt that he, a prisoner in the midst of his enemies and under the sentence of death, if consulted as to his next step or resource, could answer more wisely than all his countrymen beside. He best understood his position; he contemplated it most calmly. Comparatively, all other men, North and South, were beside themselves.”
—Henry David Thoreau (1817–1862)
“We may say that feelings have two kinds of intensity. One is the intensity of the feeling itself, by which loud sounds are distinguished from faint ones, luminous colors from dark ones, highly chromatic colors from almost neutral tints, etc. The other is the intensity of consciousness that lays hold of the feeling, which makes the ticking of a watch actually heard infinitely more vivid than a cannon shot remembered to have been heard a few minutes ago.”
—Charles Sanders Peirce (1839–1914)