It's called "tides". The phenomenon is caused by the gravitational attraction of the moon and the sun.
Please repeat 5th grade.
I knew an Ivy League graduate who was a federal agency head in the Clinton administration who didn’t understand the difference between saltwater and freshwater. Seriously. Her job had nothing to do with the environment but her ignorance of the world around her was disturbing, to say the least. I’m sure she would take the hysterical sea level rise assertions hook, line and sinker, even though there is no empirical evidence supporting it.