Analysis of the effectiveness of alert messages issued by tsunami service providers: a case study from May 2nd, 2020 South Crete earthquake and tsunami alert for Egypt

At 12:51 UTC on May 2nd, 2020, an offshore earthquake of magnitude Mw = 6.7 and focal depth of around 10 km occurred south of the island of Crete (Greece). The initial tsunami alert message (TAMs) received by the Egyptian National Research Institute of Astronomy and Geophysics—NRIAG (i.e. the National Tsunami Warning Focal Point for Egypt) was issued by the Geodynamic Institute of the National Observatory of Athens (NOA-HLNTWC), and was based on preliminary, a rather inaccurate hypocenter and magnitude estimates. About 36 min after the earthquake, a follow-up message with an increased tsunami warning level was issued; the updated warning was motivated by a significant revision of hypocenter and magnitude estimates rather than on standard incoming sea-level data processing. This study's main objective is to evaluate the North-East Atlantic, Mediterranean and connected Seas (NEAMTWS) tsunami service providers (TSPs) dissemination process of tsunami alert messages (TAMs) basin-wide and in...