earth-shattering
causing the ground to shake, for example because of an explosion:
The cannon produced an earth-shaking boom and a big cloud of white smoke.
The giant wave broke with an earthshaking force that could be heard several miles away.
Climate change is having an earth-shaking effect on agriculture in this region.
His conclusions may not be not earth-shaking, but they are important and relevant.
The conclusions of the investigation are hardly earthshaking.
The fireworks exploded with an earth-shaking roar.
The mine was struck by an earthshaking collapse.

SMART Vocabulary: related words and phrases

Very important or urgent
all-important
at all costsidiom
be a matter of life and/or deathidiom
cardinally
chief
imperative
last but not leastidiom
leading
life-altering
life-and-death
life-changing
overriding
primary
prime
principally
prior
prized
seminal
tectonic
weighty

You can also find related words, phrases, and synonyms in the topics:

Surprising and shocking
Shaking, swinging and vibrating