46 Tsunami: Thera Island (Santorini), Greece

46 AD July 6. Thera. At the same time as an eclipse of the Moon, probably following a subdued eruption, an islet, which became known as Theia, rose up from the sea between Thera and Therasia in the Cyclades.

This event is well documented by contemporary authors, including Seneca, who confirms that it happened in his own time and during the consulship of Valerius Asiaticus (AD 46). Dio Cassius dates it Roman year 800 (AD 47), while St Jerome gives the fifth year of Olympiad CCVI (AD 45), and notes the length of the island as 30 stadia (5.5 km). Orosius (writing early in the fifth century AD) dates it to the fifth year of Claudius (AD 45-46).

Since Aurelis Victor mentions that it happened on the same night as a lunar eclipse, there is a chance of dating the eruption accurately. Schove and Fletcher (1987, 9-11) derive several dates, noting that the most popular is 31 December AD 46, because this would embrace both Seneca's date of AD 46 and Dio's of AD 47. However, he thinks that 6 July AD 46 is more probable because the eclipse would have been distinctly noticeable by about 8.53 pm, and consequently more likely to be recorded.

One must beware of confusing this eruption with that of Hiera in 199-198 BC, since the two occurrences were very similar in nature. Pliny mentions both, but the dates in the relevant passage are notoriously unreliable. Pliny's date, 8 July of the 110th year after the fourth year of Olympiad CXLV, works out as AD 3. This is due in part to a scribal error in an early copy of Pliny's works, when many events were assigned to Olympiad CXXXV.

Modern cataloguers associated this eruption with the Crete earthquake of 62-64, dating it 53/52/66. Guidoboni (1989, 661-662), Guidoboni et al. (1994, 193-194) associate this eruption at Thera with the Crete earthquake of 62-64, dating it 53/52/66 for which I have no evidence.

(above from reference #9116)

46 A.D. Crete. Sea withdrawal in Crete. (reference #4139)

Philostratus Flavius refers that on July 6 (46) at about 12 am a violent earthquake shook Crete and the sea receded for about 1.3 km from the shoreline. (reference #9158)

46 A.D. South coasts of Crete. (reference #15)

46 A.D. South coasts of Crete. Earthquake 36 deg 1/4 min N, 25 deg 1/4 min E, intensity VII. (reference #20)

46 A.D. Cyclades (Santorin), 36 1/2 deg N, 25 1/2 deg E. An earthquake, which triggered an explosion of Santorini,

was felt on Crete; the shock was followed by a tsunami preceded by a withdrawal of the water of about 100 m. (reference #109)

46 A.D. Northern Crete. Earthquake 36.4N, 25.4E, magnitude 6.2. Eruption of Santorini volcano. (reference #330)

46 A.D. South Aegean Sea. Earthquake 36 deg 24 min N, 25 deg 24 min E. Sea withdrawal. (reference #2427)

62 A.D. (possibly 46 or 66). Aegean Sea, Island of Thira. The eruption of the volcano of Santorini was accompanied by an earthquake felt strongly on the Island of Crete. Considerable destruction in Knossos. The sea in Lebena on the southern coast of the Island of Crete retreated approximately 100 m from the waterline.

Earthquake 36.5N 25E, magnitude 6.7, intensity VII, tsunami intensity iv, event validity 2. (reference #2130)