初しょ動どう

noun

initial response; first action

Used for the earliest actions taken in response to a crisis, disaster, or important event. Often appears in news and emergency contexts.

• 地じ震しん発はっ生せい後ごの初しょ動どうが被ひ害がいの大おおきさを左さ右ゆうする。

  The initial response after an earthquake determines the scale of the damage.

• 警けい察さつの初しょ動どう捜そう査さが事じ件けん解かい決けつの鍵かぎとなった。

  The police's initial investigation was key to solving the case.

noun

preliminary tremor; initial shock

Specifically refers to the first detectable seismic wave or tremor before the main earthquake. Technical term used in seismology.

• 初しょ動どうの波は形けいから震しん源げんの位い置ちを推すい定ていする。

  The location of the epicenter is estimated from the waveform of the preliminary tremor.