The undersea volcano near the main island of Tonga is one of 36 in the area but vulcanologists in the area say historical data suggests it is unlikely to cause a tsunami.
The fireworks from this undersea volcano near the main island of Tonga have blasted it into the league of local tourist attractions.
It's sending plumes of ash, steam and smoke kilometres up into the sky.
At least two airline flights have been diverted to avoid the debris.
Vulcanologists say a tsunami is unlikely but can't be completely ruled out.
SOUNDBITE: Tony Hurst, vulcanologist, saying (English):
"They don't seem to cause tsunamis very often but it is a possibility."
The volcano is one of 36 in the area.
Tonga is on the Pacific Ring of Fire, a series of tectonic plates and volcanic earth structures that stretches for 40, 000 kilometres.