These give you an idea of the shockwave that went out & the scale of the eruption:
An undersea volcano erupted in spectacular fashion near the Pacific nation of Tonga on Saturday, sending large tsunami waves crashing across the shore and people rushing to higher ground.
There were no immediate reports of injuries or the extent of the damage as communications with the small nation remained problematic. Video posted to social media showed large waves washing ashore in coastal areas, swirling around homes and buildings.
As of three hours ago the eruption had stretched over a radius of 161 miles. Tonga consists of over 170+ islands and from what I've looked up this particular volcanic island (Hunga Tonga-Hunga Haʻapai) was not inhabited, though obviously the fallout is going to affect tens of thousands. Scary stuff.