The island is long; wide; and covers . It is above a hotspot in the Earth's crust. The Piton de la Fournaise, a shield volcano on the eastern end of Réunion Island, rises more than above sea level and is sometimes called a sister to Hawaiian volcanoes because of the similarity of climate and volcanic nature. It has erupted more than 100 times since 1640, and is under constant monitoring, most recently erupting on 2 April 2020. During another eruption in April 2007, the lava flow was estimated at per day. The hotspot that fuels Piton de la Fournaise also created the islands of Mauritius and Rodrigues.