noun
seismic intensity scale
Refers to the Japanese scale from 0 (imperceptible) to 7 (disastrous). Often used in earthquake reports and disaster prevention contexts.
See also: 震度
気象庁は震度階級を用いて地震の揺れの強さを発表する。
The Japan Meteorological Agency announces the strength of earthquake shaking using the seismic intensity scale.
震度 refers to a specific intensity level (e.g., 震度5弱), while 震度階級 is the scale itself.
Compound of 震度 (seismic intensity) and 階級 (class, rank).