Andersen's most recognized work has been on volcanoes in Indonesia, where he has documented volcanic eruptions since 2008. His documentary photography and observations on volcanoes include Merapi, The Tengger Caldera, Tangkuban Perahu, Dieng Volcanic Complex and Anak Krakatau. On 22 December 2018, Andersen documented the volcanic-eruption of Anak Krakatau, that triggered the significant Sunda Strait tsunami. Following the event, his