At 01:43 Italian time on 21 May 2020 an earthquake of magnitude 5.5 was located in the Ionian Sea, offshore Greek coast, epicenter at geographical coordinates (lat, lon) 35.21, 20.24 at a hypocentral depth of 10 km.
Although far from the Italian coast (almost 500 km), the earthquake was felt in some areas of southern Italy, especially in Puglia and eastern Sicily, as reported by our correspondents of "Hai sentito il terremoto"?
Magnitude of the event, just above minimum attention threshold, triggered the Tsunami Alert Centre service which: within a few minutes after the earthquake, sent an INFORMATION message to the Civil Protection Department and to the Mediterranean countries. Remember that the information message does not fall within the alert levels, but indicates that: if an earthquake occurs, a tsunami is considered unlikely, based on the estimation criteria adopted at international level.
In the map below, the star represents the epicentre of the earthquake where the concentric circles in various shades of green start from. This is the Isocrone of the Tsunami (in this case it was not generated) and it shows the time of propagation of the possible tsunami. Just look the image, we realize the tsunami speed travel in sea, if it were generated, would take less than an hour to reach the Italian coast.
The green triangles on the coast are the observation points of the sea, "Forecast Point" (Green this time because there's no alert).
The previous news, published on May 15, 2020, focused on the oceanic subduction process and associated seismic sources, active in Ionian Sea and on the ( relatively low) possibility that strong earthquakes and tsunamis will be generated in that small subductive part (Ionian Arc).
More information about this (in Italian) can be found here: INGVterremoti.