WELLINGTON, New Zealand (AP) — The tsunami threat around the Pacific from a huge undersea volcanic eruption receded Sunday, but the massive ash cloud covering the tiny island nation of Tonga prevented surveillance flights from New Zealand to assess the extent of the damage.

Satellite images showed the spectacular eruption Saturday evening, with a plume of ash, steam and gas rising like a mushroom above the blue Pacific waters. A sonic boom could be heard as far away as Alaska.