From the Latin for "shake", it's a synonym for earthquake
Although shake and quake are near synonyms, shake is the less violent of the ... 
Tremble and vibrate are derived from Latin words, tremulus,... [DOC] [TLE] temblor - Memidex dictionary/thesaurus [PAR] "temblor" definition: shaking and vibration at the surface of the earth resulting 
from ... a shaking or trembling of the earth that is volcanic or tectonic in origin .... 
earthquake, from temblar, to shake, from Vulgar Latin *tremulre, from Latin 
tremulus... [DOC] [TLE] Seismo- | Define Seismo- at Dictionary.com [PAR] Seismo- definition, a combining form meaning earthquake, used in the 
formation of ... form of Greek seismos "a shaking, shock; an earthquake," from 
seiein "to shake," from PIE ... What mistaken pronunciation gave this character its 
name?