A review of tsunami early warning at the local level - Key actors, dissemination pathways, and remaining challenges

At the International Symposium on the Lessons Learnt from the 2018 Tsunamis in Palu and Sunda Strait, organised by IOC-UNESCO, experts identified the need for a critical dialogue on the future direction of tsunami warning systems, especially for events other than tectonic origins and with short warning times. This first phase of a longer-term study was initiated to develop a better understanding of tsunami early warning at the local level in countries exposed to a tsunami risk. This desk study involved a systematic literature review of academic publications from 2005 to 2021, and a narrative literature review to examine policy and guidance reports on tsunami early warning. Seven guiding research questions were identified to set the boundaries of the research and provide a clear framework for the review. The draft questions were reviewed and, through several iterations, refined by academics and representatives of working groups and technical agencies involved in tsunami early warning. The findings reveal the characteristics of the literature on tsunami early warning at the local level, as well as insights into how early warning approaches vary across Ocean Basins and between countries. The results revealed substantial challenges that hinder effective tsunami early warning at the local level, such as inadequate coordination of actors. Among several areas for improvement, the need to promote a culture for self-evacuation has been identified as a practical solution to face nearfield tsunamis. The results of this analysis will inform further detailed empirical investigations to provide contemporary insights on the status of tsunami early warning at the local level in different countries.