According to the website of the Smithsonian Museum of Natural History, the volcanic eruption took place about 65 kilometers north of Tonga's capital, Nuku'alofa.

Hunga Tonga and Hunga Ha'apai are the names of twin volcanic islands on the edge of a submarine caldera which caved in during past eruptions.

The museum says the highest point on Hunga Tonga stands about 144 meters above sea level.

It says the volcano frequently erupted in the past and that a new islet formed between the two islands during underwater eruptions from December 2014 through January 2015.

The museum says activity has continued intermittently on the volcano since last December.

The Smithsonian Museum is conducting research on volcanos around the globe.