New Islands Formed in the Past 20 Years

Hunga Tonga

On Dec. 19, 2014, an undersea volcano called Hunga Tonga-Hunga Haʻapai began erupting in the South Pacific island nation of Tonga for the second time in five years. It started with a white steam plume rising out of the ocean. Over the next few weeks, it intensified with ash plumes reaching 30,000 feet, followed by large rocks and thick ash spewing hundreds of feet into the air. By Jan. 16, 2015, a rocky new island had formed, measuring over a mile long and standing more than 300 feet above sea level. By the end of January, it had spread to join another nearby island, and the volcano crater in its center had filled with sulfurous emerald water. Two months later, visitors reported that the island was still warm to the touch and birds were already nesting on it.