EQF

Although I didn't check his exact curve, it looks like the
Grand Unification site is examining the usual thing.
The lunar and solar tides interfere so that there is a 14-day period to the oscillations of the envelope of the tidal stresses (or strains, or accelerations). This is the hundred-year old theory, and there is nothing special about accelerations, in fact they lead to no stress unless there is differential acceleration.

He got his units wrong, as well as non-standard (per day cubed?).

John