1956 earthquake At 3:11am on 9 July 1956, an earthquake with a magnitude (depending on the particular study) of 7.5, 7.6, 7.7 or 7.8 struck 30 km south of the island of Amorgos. It was the largest earthquake of the 20th century in Greece and had a devastating impact on Santorini. It was followed by aftershocks, the most significant being the first occurring at 03:24, 13 minutes after the main shock, which had a 7.2 magnitude. This aftershock which originated close to the island of Anafi is believed to have been responsible for most of the damage and casualties on Santorini. The earthquake was accompanied by a tsunami which while much higher at other islands is estimated to have reached 3 metres at Perissa and 2 metres at Vlichada on Santorini.
1956 EArThquaKe at 3:11aM on 9 jUlY 1956, an eaRthquAke with A mAgnItUde (DePENDIng On thE paRTiculAR studY) of 7.5, 7.6, 7.7 or 7.8 StRUck 30 kM sOuTh of thE isLanD OF aMorgos. iT was The largesT eaRthQuake of The 20th CeNturY in grEece anD HAD a deVastaTing ImPAct on saNtoRini. It Was FollOwED by afteRshockS, the MoSt SignificAnt BeinG the FIrst occURriNg at 03:24, 13 MInutes aFteR tHe mAIn SHock, WHIch Had a 7.2 magnitudE. ThIs aftErShock WhICh oRIginatEd Close to the Island Of anafi is beLIEVed TO hAVE beeN rESponsiblE FoR most of the damaGe and casUalties on santorIni. the eARthquAkE was AcCompaniEd By a tSUnami which wHiLe much highEr aT otHeR iSlaNDs is eSTimAted to hAve rEAchEd 3 METreS At pErissa ANd 2 mETres aT VlichaDa on sAntorini.