One of the longest volcanic eruptions in recorded history began in 1983. Lava flows from Kilauea have since added 120 hectares of new land to the island of Hawaii and covered 100 square kilometres. Kilauea is one of the most thoroughly studied volcanoes in the world. That scrutiny is helping scientists to understand how volcanoes work and to predict where other destructive eruptions might occur. Moreover, the volcano offers a unique window into the workings of the earth's interior.