[bd476]

Check this out, OP. This is technically a tidal wave, yet it is not a tsunami. This "tidal bore" occurs in a river in China every year.

Here you'll see people lining up to watch the event which turns out to be an unwise decision.

Tidal Bore Flooding

[bd476]

Be sure to click on the photo, and turn on the volume on your computer. It's a startling video.