noun
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.
その地域は烈震に見舞われた。
The region was struck by a disastrous earthquake.
烈震で多くの建物が倒壊した。
Many buildings collapsed in the violent earthquake.
Also means a severe shock or violent quake, and is often used figuratively for social or political upheaval; 烈震 is more directly earthquake-focused.
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.