If it has a period not tied to the rotation of the earth (ie tides) then it is not a change in sea level but a wave. And Tsunami does not translate as "tidal"

If it has a period not tied to the rotation of the earth (ie tides) then it is not a change in sea level but a wave. And Tsunami does not translate as "tidal" wave. It means "port wave" and has nothing to do with tides whatsoever.