One could look up on the USGS website a similar EQ (magnitude wise) and look at their calculation of how much energy was involved. Then use analogy to estimate the Mayotte event.
But consider this: To simply move a mass in a linear manner, you apply the equation for mass, force, velocity, acceleration.
But to set a mass into vibration might be a totally different deal requiring much less energy. Think pushing a playground swing. Each push adds a modest amount of energy but the swing keeps swinging, in an ever-higher arc.
That's a different model to evaluate how energy can put mass into an oscillatory motion.