noun
severe earthquake; strong earthquake
Refers to an earthquake of high intensity, typically used in news reports and seismology. In Japan's seismic intensity scale, it corresponds to upper 5 (強) or higher.
昨夜、東北地方で強震がありました。
A strong earthquake struck the Tohoku region last night.
強震に備えて家具を固定しておきましょう。
Secure your furniture in preparation for a severe earthquake.