Copernicus (ESA) satellite imagery taken on May 22nd, 2026, that shows the discoloured seawater and pumice rafts above the eruption site.
The location of the eruption site (star) on the geological map (left) and a bathymetric map. Image credits: Philipp Brandl.
Underwater Volcano, First Identified by Seafloor Geological Map, Erupts in the Bismarck Sea
Since May 8th, 2026, plumes of steam and gas were observed rising above parts of the northern central Bismarck Sea off the coast of Papua New Guinea. Later satellite imagery has shown discoloured seawater with patches of floating pumice extending over an area of 250 square kilometres.
Thanks to a recently produced geological map of the seafloor in this region (Brandl et al., 2024) that was created as part of a collaboration between GEOMAR Helmholtz Centre for Ocean Research Kiel and the University of Ottawa, the site of the eruption could be linked to a series of volcanic ridges known as the “Titan Ridges” that occur close to the Willaumez Transform Fault.
Although this eruption is very far from any inhabited coastlines and thus presents no danger to human populations, the event highlights the importance of seafloor geological mapping in providing context to volcanic and tectonic activity occurring in offshore areas.
Refer to the following article published by GEOMAR for more details: https://www.geomar.de/en/news/article/possible-eruption-of-an-underwater-volcano-in-the-bismarck-sea
The geological map and its accompanying paper can be found in:
Brandl, P. A., Hannington, M. D., Kraetschell, A., & Sander, S. G. (2024). A New Geological Map of the Marginal Basins of Eastern Papua New Guinea: Implications for Crustal Accretion and Mineral Endowment at Arc–Continent Collisions. Lithosphere, 2024(4). DOI: 10.2113/2024/lithosphere_2024_145
