Ocean-wave phenomenon around Japan due to the 2022 Tonga eruption observed by the wide and dense ocean-bottom pressure gauge networks

• DOI: 10.1186/s40623-022-01663-w
• Publication Date: 2022-07-04T11:13:38Z
• Authors: Hisahiko Kubo; Tatsuya Kubota; Wataru Suzuki; Shin Aoi; Osamu Sandanbata; Naotaka Chikasada; Hideki Ueda
• Keywords: Tide gauge

Abstract Ocean-bottom pressure gauges of wide and dense ocean-bottom observation networks around Japan, S-net DONET, observed ocean waves caused by the Tonga eruption that started at approximately 13:00 JST (UTC + 0900) on January 15, 2022. We scrutinized waveform records arriving to evaluate their nature found two significant disturbances between 20:00 21:00 after 22:00. The first disturbance with a positive-polarity pulse dominated long-period components (1000–3000 s) arrived DONET stations from southeast, corresponding direction short great circle Japan. This arrival was much earlier than expected for direct tsunami volcano can be explained assuming propagated along path velocity 300 m/s. After 22:00, phases relatively shorter period (< 1000 southeast in both networks. In another phase south–southeast 23:30 (approximately 500 s). Most near-trench recorded peak amplitude during disturbance, whereas near-coast amplitudes changes increased as water depth decreases. amplification behavior differed second disturbances, which is attributed differences natures air waves. study also several arrivals air-wave correlated ocean-wave phases, implies multiple pressures were generated interactions following 2022 Graphical abstract