Butt Quake 

A fart which is so loud and powerful that it reverberates the entire area around the expeller.

Robin: Oh my God, everything in the house is shaking, it's an earth quake!
Chris: Don't worry about it, that was just a butt quake I let loose downstairs.

Local Newscaster: Today we mourn the loss of the twenty people that were killed on this day last year when an unsuspecting local man released a butt quake while on board a city bus.

Butt Quake by MerchantofVenice5 February 4, 2013

Buttquake 

The ripples that propagate across the female hindquarters caused by the rhythmic spasms of orgasm.

Me: OMG! That was a 6.5 buttquake!!
Her: of course, you made me cum so hard I queefed at a frequency that can only be heard by dogs!

Buttquake by Doug E. Stile October 18, 2018

Buttquake 

Noun. The ripple effect you receive while having doggy style intercourse or slapping a hoe's ass.

I was banging Sheila the other night from behind and she had some epic buttquake.

Buttquake by 1337x1 October 19, 2011