tremor

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tremor

a minor earthquake

Tremor

 

an involuntary trembling of the entire body or parts of it. Tremors are characteristically rhythmic and stereotypic; usually they have a narrow range, most often affecting the fingers, eyelids, tongue, lower jaw, and head. In healthy subjects, tremors may be caused by muscular strain, emotional excitement, or exposure to cold. Pathological tremors may be symptoms of chronic alcoholism, thyrotoxicosis, neurotic states, acute infections, and such diseases as parkinsonism. The symptom is treated by treating the primary disease.

Eye tremor is an involuntary rapid movement of the eyeball in relation to the optic axis; its frequency is from 20 to 150 Hz, and its amplitude, from 5 to 15 seconds of arc. Visual perception itself depends to a significant degree on eye tremor, which produces constant changes in the illuminance of certain photoreceptors—that is, the photoreceptors located at the variously illuminated points of the retinal periphery. An image whose projection on the retina remains completely stable for more than a few seconds ceases to be perceived by the visual centers of the brain.

tremor

[′trem·ər]
(geophysics)
A minor earthquake. Also known as earthquake tremor; earth tremor.
(medicine)
Involuntary, rhythmic trembling of voluntary muscles resulting from alternate contraction and relaxation of opposing muscle groups.
References in periodicals archive ?
According to the Civil Engineering Department of UCD, the country's existing building codes don't cover the possibility of earth tremors.
Earth tremors are considered a fact of life in Taiwan.
Pot hunters and earth tremors have ravaged the Southern Temple in Petra, Jordan.
What about the air pollution from heavy trucks and flaring and the risk of earth tremors and subsidence - Who would want to insure our houses?
There are also worries that the fracking process can cause small earth tremors.
But the move is set to face opposition from campaigners who argue that fracking, which involves pumping water, sand and chemicals into rock, could trigger earth tremors or pollute water supplies.
The tiny amount of fracking carried out has already caused earth tremors in what has been, up to now, a very stable part of the world.
Today, though, it's controversial as there are concerns fracking can cause small earth tremors and the chemicals used could contaminate ground water around the fracking site (the term they use - not what the protesters call it.
Earth tremors measuring two to three points on the Richter scale were felt in Yuzhno-Sakhalinsk.
EARTH tremors that shook Blackpool were almost certainly caused by a company drilling for gas, experts said yesterday.
The earth tremors were felt in Andizhan and Fergana regions as 5 scores, in Namangan region - 4 scores, in Tashkent city - 5 scores.