Satellite imagery shows the island of Hunga Tonga Hunga Ha'apai has grown in size as the underwater volcano erupts into its sixth day.
Tonga's head geologist Taniela Kula has all week been monitoring the volcano, which erupted again this morning.
While observations have had to be kept to a distance, new satellite imagery shows the island's land mass has grown since Monday.
"The island has grown 300 to 600 metres to the eastern side. So it has widened up a bit. [The debris] has been building up the island, building up the rim of the vents," Kula said.