Battle five trainers in the desert, and it’s yours
There’s so many TMs in Pokemon Scarlet & Violet, it can get really confusing keeping track of them all. Some of them are found out in the wild, just laying around. A few of them are tucked away in hidden areas. And others are found through more esoteric and taxing means.
Finding Earthquake (TM 149) isn’t particularly tough, you just need to know where to look.
You can find Earthquake at the northern Cascarrafa Pokecenter after defeating five trainers in the desert
Phew! That’s a mouthful. But it really does explain the entire situation.
To get your hands on Earthquake, you’ll need to defeat five trainers in the Asado desert, in the western portion of Paldea. If you’re reading this, you’re probably coming at it from the angle of being immersed in the endgame, so you can steamroll these trainers in minutes (like everything in Scarlet & Violet, they’re at a fixed level). Start out on your quest by crossing the bridge right near the flightpath into the desert, then turn left and find your first trainer battle. Head along the desert in a counterclockwise position, and you’ll easily find four more trainers to fight.
The NPC that gives you Earthquake is actually at the northern Cascarrafa flight path waypoint, and you can find the exact location in the gallery above (with the red arrow pointing at it). Eligible trainers can be fought in the zone that’s circled in that same image.