Global Volcanism Program | Image GVP-01693
During 5-18 September 1990 Ambrym was observed to be ejecting ash and blocks from Niri Mbwelesu crater, which formed adjacent to Mbwelesu crater in 1989 when Mbwelesu was also active. It no longer contained an active lava lake. Mbwelesu, Niri Mbwelesu, and Niri Mbwelesu Taten craters remained almost constantly active into 1991.
Photo by Michel Lardy, 1990 (ORSTROM, Vanuatu).