disastrous earthquake; severe earthquake; violent earthquake
A formal or disaster-reporting term for a very strong, destructive earthquake; more specific and heavier in tone than the general word 地震.
The region was struck by a disastrous earthquake.
Many buildings collapsed in the violent earthquake.
A disastrous earthquake occurred in that region, and many buildings collapsed.
The town was struck by a disastrous earthquake last night.
激震 denotes the very highest level of shaking on the old intensity scale (and is often used figuratively for shocks), whereas 烈震 is the level just below it and stays literal.
地震 is the neutral, general word for any earthquake, while 烈震 specifically singles out a violently destructive one.
微震 refers to a barely perceptible tremor, the opposite end of the intensity scale from the violently destructive 烈震.
強震 is the intensity level just below 烈震 on the old JMA scale, so learners easily mix up which term denotes the stronger quake.
A Sino-Japanese compound: 烈 conveys violent or intense force, and 震 means shaking or earthquake. This is a transparent meaning-based spelling rather than evidence of a specific historical origin.