I've seen "possible tsunami" pre-warnings, and a sea level gauge at/near Lembar showing sea level oscillations - so I would recommend keeping a close watch on some information source that's better than HN comment threads, yes.

Correct, but also, I’d bet there is a lurking tsunami expert here somewhere. Nothing is ever too niche for HN.

There's a tsunami warning list you can sign up for. As well as global earthquake alerts. In my experience they arrive very quickly

Usually earthquakes on land don't trigger tsunamis but are more damaging locally