While I don't remember the relative probabilities, the next big earthquake in the Pacific Northwest and Northern California region is expected to be much more intense: https://en.wikipedia.org/wiki/Megathrust_earthquake#The_Big_...

In the list of worst predictable natural disasters in the Continental US, it rates one above the expected earthquakes to the south, the result of two plates mostly sliding past each other: https://en.wikipedia.org/wiki/San_Andreas_fault

Worse, in part because we aren't at all prepared for it (aside from I hope more serious buildings) would be a return of major earthquakes in mid-West: https://en.wikipedia.org/wiki/New_Madrid_Seismic_Zone (something I pay attention to since that's on the other side of Missouri from me).

I forget one of them, and the worst, which few in the US would survive, and where being in Australia might not be a bad idea at all, would be a return of the Yellowstone Supervolcano: https://en.wikipedia.org/wiki/Yellowstone_Caldera

Supposedly that is why AWS located their infrastructure in Oregon, after starting in NoVa. They optimize for "lowest probability of disaster" before considering other options like cost (primarily power) and connectivity.