seismic

1. ADJ Seismic means caused by or relating to an earthquake. 地震的; 地震引起的[ADJ n]

Earthquakes produce two types of seismic waves. 地震产生两种类型的地震波。

2. ADJ A seismic shift or change is a very sudden or dramatic change. 突然的[usu ADJ n]

I have never seen such a seismic shift in public opinion in such a short period of time. 我从来没有见过公众舆论在这么短的时间内发生如此突然的转变。