Expedition to Ambrym Volcano, Vanuatu in 2025

We're back on Ambrym Island in 2025 to document the geological changes that have unfolded since our last expedition. Upon visiting the Ambrym complex, significant changes were observed at Benbow, Mbogon Niri Mbwelesu (Taten), and Marum's Mbwelesu and Niri Mbwelesu craters, all of which display ongoing, vigorous post-2018 volcanic activity. Benbow Crater showed striking changes since the last visit, with accelerated erosion on its ash plains due to the collapse of a protective barrier, while multiple eruptions in 2024 have deposited substantial new lava, raising the crater floor by 20-30 meters, with four distinct active vents now identified, accompanied by extensive fracturing and degassing. In contrast, the formerly difficult-to-observe Mbogon Niri Mbwelesu (Taten) now has significantly reduced gas output, revealing a larger, unstable crater where a brief April 2024 eruption produced A'a lava flows with pahoehoe upper textures, while a nearby southern zone remains barren with persistent hydrothermal activity; finally, while the main access to Marum's craters is blocked by erosion and cliffs, drone footage confirmed an April 2024 eruption in Marum's Mbwelesu Crater, showing multiple lava flows and fractures from several vents, and noted that Niri Mbwelesu Crater, despite being partially buried by landslides, currently exhibits the lowest activity levels.