The GNSS enhanced Tsunami Early Warning System (GeTEWS) Oceania Initiative

The GeTEWS Oceania Initiative is an international effort under the IUGG Commission on Geophysical Risk and Sustainability. It aims to strengthen tsunami monitoring and early warning capabilities across the Pacific region through the deployment and integration of real-time GNSS observation networks.Oceania occupies a unique and highly vulnerable position, being both a source and a recipient of tsunamis generated by the intense tectonic and volcanic activity of the Pacific Ring of Fire. Recent events, including the 2022 Tonga eruption and tsunamis, have highlighted critical gaps in existing tsunami early warning systems, particularly for non-seismic and complex multi-source tsunamis.Continuous GNSS observations can provide real-time estimates of crustal deformation, and atmospheric variability, offering a powerful complement to existing tsunami early warning systems. Despite this potential, GNSS infrastructure across Oceania remains sparse compared to other tsunami-prone regions.The GeTEWS Oceania Initiative addresses this gap by promoting the development of a sustainable, regionally coordinated network of continuously operating GNSS stations and real-time analysis centers, designed to support tsunami early warning and disaster risk reduction. The initiative builds on two decades of progress in tsunami science and early warning, as synthesized during the GeTEWS 2017 Workshop, and incorporating lessons learned from recent major events and aligning with international priorities for multi-hazard monitoring.The initiative has entered its implementation phase through two complementary pilot projects. The Tonga GNSS Network Pilot Project, led by the Ministry of Lands and Natural Resources of the Kingdom of Tonga in collaboration with Central Washington University and IUGG, has deployed four GNSS stations (with further expansion planned) and established real-time data streaming to analysis centers. A second pilot project focuses on federating existing GNSS infrastructures across Oceania into a “Network of Networks,” enabling data sharing among regional and global systems and revitalizing underutilized or dormant networks, such as those in Vanuatu.By fostering multinational collaboration, shared data infrastructures, sustainable GNSS maintenance, reliable broadband connectivity, and integrated regional computational and analysis capabilities, the GeTEWS Oceania Initiative aims to enhance tsunami detection and monitoring, improve early warning performance for both seismic and non-seismic tsunamis, and strengthen long-term resilience to tsunami hazards across Pacific coastal communities.