The adj earthshaking has 2 senses? (first 1 from tagged texts)
1. (1) earthshaking
(loud enough to shake the very earth)
2. earthshaking, world-shaking, world-shattering
(sufficiently significant to affect the whole world; "earthshaking proposals"; "the contest was no world-shaking affair"; "the conversation...could hardly be called world-shattering")