No tsunami threat following 5.2 magnitude earthquake on Big Island

[FBaggins]

5. It would have to be almost 100 times larger

To create a tsunami that might do damage

But it’s more complicated than that. The type of earthquake matters too. The strike-slip type you get in CA aren’t likely to do so even in the 7s... and neither are volcanic ones (again, unless they cause part of an island to collapse). It’s the fault lines where one plate is diving under another that cause the devastating waves... but those faults are along plate boundaries thousands of miles away.