It wasn't a tidal wave. Tidal waves are related to the gravity of the moon. Tsunamis (or seismic sea waves) are related to volcanic eruptions, earthquakes or sea floor disturbances.
Many years ago I was the news director of a radio station in Mobile, AL. One of the major seismic centers in the US in those days was at Spring Hill College, also in Mobile. From time to time I had occasion to call the college and speak with the priest who was in charge of the seismology department there. He would become practically violent if you used the term 'tidal wave'. It was like he considered himself to be on a mission directly from God to make certain everyone called these events by their real name 'tsunamis'. After you got past the initial indoctrination to the proper terminology for these events he was very personable, very knowledgeable and willing to talk at length about them. I can never hear of one of these without thinking about that priest!
To go with common usage, what you describe aren't "tidal waves" but rather, tides. Until two days ago, I never understood why tsunamis were ever called tidal waves at all, but now I do.