100ft megathrust tsunami threat hiding off the West Coast — shown in staggering simulation

A chilling new simulation shows how a massive megathrust earthquake could unleash a devastating tsunami on the West Coast.

The canimation from cutawaynature’s Instagram account shows what happens deep beneath the ocean when two tectonic plates lock, with one slowly forced beneath the other, according to Surfer.com.

Enormous pressure can quietly build along the fault for decades with virtually no indication at the surface of what is happening below.

Then it ruptures.

The simulation shows the overriding plate suddenly snapping upward, lifting the seabed and violently displacing the massive column of water above.

The tsunami initially appears as a wide, barely noticeable swell racing through the deep ocean.

But as it reaches shallow water, the threat becomes clear: the sea pulls away from the coast before surging back toward land.

“A wordless geological cutaway of a megathrust tsunami forming in real time and deep time,” the video’s caption reads.

It shows a locked fault storing strain before “the overriding plate snap[s] upward, the seabed lift[s] as one continuous mass” and the tsunami transforms “from a nearly invisible deep-ocean wave into coastal drawdown and surge.”

The small-scale demonstration breaks down the large geological event to show the forces that cause it.

“No narration. No music,” the caption reads. “Just rock, water, pressure and motion.”