The main outcomes of the project, so far, are:
1. Creation of a database of high-quality 1-min measurements of sea level. This is a database of unprecedented quality for European sea level data measured at time steps of 1-20 minutes, and it is likely to be used for numerous research activities in the future. The database will be made publicly available through existing sea level data services.
2. Improved understanding of the importance of sub-hourly sea level oscillations. Traditionally, extreme sea levels have been studied using either low-frequency (hourly) sea level series (when studying storm surges) or high-frequency series (when studying various forms of tsunamis, including meteotsunamis). In SHExtreme, we examine the joint effect of low-frequency and high-frequency sea-level oscillations, and show that processes at both scales can contribute significantly to overall extremes and should be evaluated together when assessing hazards caused by extreme sea levels.
3. Research on tsunamis caused by the eruption of the Hunga Tonga-Hunga Ha'apai volcano. The eruption occurred on January 15, 2022, and triggered two types of tsunamis: a tsunami generated by the initial displacement of the water level due to the submarine eruption (this tsunami reached heights of up to 90 m and was felt along the coasts of the Pacific Ocean), and tsunamis triggered by atmospheric waves that circled the Earth several times. As part of the project, we conducted some of the first published research on this topic.
4. Educational activities for local island communities. As part of the SHExtreme project, we have made significant efforts to promote marine research at the local level. We do this through an activity called " Oceanographers on the island" (
https://www.facebook.com/oceanografi/(opens in new window)). We visit islands and organise one- to two-day workshops for school children, game nights on oceans and ecology, and popular lectures for local people. So far, we have visited six Croatian islands, reaching several hundred children and islanders. We plan to continue these activities throughout the project and beyond.
5. Meteotsunami catalogue - a unique meteotsunami catalogue was created for the Adriatic coast (
https://projekti.pmfst.unist.hr/floods/meteotsunamis/(opens in new window)). This is one of the first meteotsunami catalogues, and we hope that it will serve as a base catalogue to which meteotsunami events from other European coasts will be added. The catalogue contains detailed information on 36 meteotsunami events measured along the Adriatic coast. A source is given for each event, along with descriptions of atmospheric and sea level variability and detailed synoptic analyses.
In summary, the SHExtreme project is the first to comprehensively investigate the contribution of under researched sub-hourly sea-level oscillations to extreme sea levels along European coasts. Our initial published analyses, as well as ongoing research, have shown that sub-hourly sea level oscillations have been unfairly omitted from sea level extremes analysis - an omission that must be corrected as soon as possible in the face of accelerated sea level rise.
