World Tonga is home to 170 islands. A new one just formed from an underwater volcanic eruption. September 27, 2022Jordan Mendoza, USA TODAYComments Off on Tonga is home to 170 islands. A new one just formed from an underwater volcanic eruption. The new island in the South Pacific has grown to be 8.6 acres with an elevation near 50 feet about sea level. Time will tell if it will last.