tidal wave 
noun
1An exceptionally large ocean wave, especially one caused by an underwater earthquake or volcanic eruption.Tsunamis, or monster tidal waves generated by volcanic eruptions, leveled Hilo in 1946 and 1961....
- We are not cursed with ice storms, hurricanes, volcano eruptions or tidal waves.
- One version, now seen as discredited, suggests it was made possible by a tidal wave caused by an underwater volcanic eruption.
1.1A widespread or overwhelming manifestation of an emotion or phenomenon: a tidal wave of crime...
- Alex is rocked by a tidal wave of emotion when he visits Benny in jail.
- She felt a tidal wave of emotions at the sight of him.
- I assumed the squealing tires belonged to him and I was hit with a tidal wave of super emotions.