In an unexpected event, Hunga-Tonga Hunga-Ha’apai, one of 22 volcanoes in the waters around the Kingdom of Tonga, erupted extremely violently on the 15th January, 2022. The eruption triggered shock waves through the atmosphere and generated a tsunami across the Pacific Ocean, as well as severing subsea fibre optic cables, leaving the nation in a blackout for several days. In April of 2022, New Zealand’s National Institute of Water and Atmospheric Research (NIWA) and The Nippon Foundation announced their mission to discover the undersea impacts of the Tonga volcanic eruption with the Tonga Eruption Seabed Mapping Project (TESMaP). The New-Zealand-led team, funded by The Nippon foundation and supported by The Nippon Foundation-GEBCO Seabed 2030 Project, aimed to investigate how much material was displaced and how the bathymetry had changed using a two-phase process. Phase 1 saw NIWA’s research vessel, the R/V Tangaroa, doing the initial survey, mapping 22,000km2 of seabed as well as assessing the impacts of the eruption on the surrounding ocean environment, from underwater topography to ecosystem structure.  

Phase 2 utilised SEA-KIT’s Uncrewed Surface Vessel, the USV Maxlimer, to conduct further mapping within the caldera in a low risk, non-invasive solution. As well as a Multibeam Echosounder, the USV was also equipped with Miniature Autonomous Plume Recorder (MAPR), which together with the water column data, indicated the areas where active venting was ongoing. Overall the data collected, both geophysical and oceanographic, will be used to better improve tsunami forecasting and better predict the blast effects of subsea volcanoes.  


 Aileen Bohan

Following the completion of her Masters in Geology, Aileen joined the INFOMAR project at the Geological Survey of Ireland where she spends the summers mapping the Irish coastal waters and the winters analysing the data. Aileen achieved her Cat A in Hydrography certificate from the Centre of Coastal and Ocean Mapping at UNH, through The Nippon Foundation-GEBCO Training Programme. Aileen remains an active member of the GEBCO community and has undertaken many surveys with The Nippon Foundation-GEBCO Seabed 2030 Project, most recently joining an Arctic Expedition. She holds the position of Chair of GEBCO’s Subcommittee on Regional Undersea Mapping.  


Kevin Mackay

Kevin is a Marine Geologist at NIWA. For over 25 years, Kevin has worked on the collection, processing and management of bathymetric data and has been involved in more than 20 expeditions, ranging from the Tropical Pacific to the Ross Sea of Antarctica. He is also the Head of The Nippon Foundation-GEBCO Seabed 2030 Pacific Data Centre and a Member of GEBCO’s Subcommittee on Undersea Feature Names.