Terri Hoover, age 9, of Matthews, North Carolina, for her question:

What is a tidal bore?

A bore is a tunnel or funnel shaped hole. And a tidal bore is caused by a funnel shaped bay or estuary along a coast line. With the help of other geographical features, such a tunnel of land may become a trap for very high tides. The tidal water sweeps in with a rushing wall of water, many feet high. This wall of advancing water is cared a tidal bore.

Tides are stronger in some parts of the globe than others. They arrive and depart at different times on different beaches around the world. But all tides are global events and those that reach the shores are merely the edges of gigantic upheavals in the deep oceans. Some shorelines happen to be in the path of extra strong ocean tides. Here, the high tides are extra high and they bash the shores with extra force. Sometimes sucha tide meets a wide river mouth, or a funnel shaped bay. The on rushing water is pushed into the opening in a heaving wall and we get a tidal bore.