March 17, 1820 Earthquake: Levkas, Greece

Note: earthquake sequence of January–March 1820

Reference #9116:

AD 1820 Jan 31 Lefkas. From this date to March 28 altogether 424 were felt in Santa Maura (Brugnatelli and Brugnatelli 1820).

AD 1820 Feb 21 Lefkas. This is the most violent shock of those felt in Santa l'vlaura during the period January to March. The shock occurred in the morning and a number of houses built of stone masonry, a part of the fortress and churches collapsed. The square in the centre of the town settled. A new islet was said to have appeared in the neighbourhood. The earthquake was felt on the mainland and in Corfu, particularly in the southern part of the island, where the yield of a spring at Drimopoli, 2.5 km south of Benitsae, was affected (Arago 1818-30, 15, 422; Brugnatelli and Brugnatelli 1820; Partsch 1887, 41; Schmidt 1879, 164).

AD 1820 Mar 17 Lefkas. A damaging aftershock occurred at 9 h in Santa Maura. According to some writers this was the worst of the shocks in Santa Maura of this period (Brugnatelli and Brugnatelli 1820)

Reference #1099:

Lists two separate earthquakes on March 17, in Levkas (mentions tsunami) and Khios (mentions storm).

Reference #4048:

1820 Feb 21. Leukada. From 31 January till 28 March, 424 shocks occurred in Leukada and fue stronger of them were those on 21 February and 17 March. The first of these two strong earthquakes caused collapse of sorne houses in Leukada and fue second destroyed a large part of the city of Leukada. It caused collapse of all houses made of stone, of churches and of part of the walls. The square which is in the middle of the city subsided (Perrey, 1848; Mallet, 1854; Barbiani and Barbiani, 1864; Kavasakales and Polimenakos, 1988).

1820 Mar, Chios. In Chios, an earthquake occurred during a thunderstorrn and caused much damage (Perrey, 1848; Mallet, 1854).

Reference #14265:

Earthquake on 9/21 February 1820. Modern authors considered that it was the most violent shock of the entire seismic sequence and, therefore, overestimated the size of the earthquake by assigning a macroseismic intensity as high as 9 (MM) and a moment magnitude of Mw = 6.4. This is because those authors attributed the most important effects of the next shock, which occurred on 17 March (N.S.), to the 21 February (N.S.) earthquake.

Earthquake on 5/17 March 1820. A memory note found in the local state archive reads as follows: A very strong earthquake destroyed a large part of the capital city of Lefkada. The central square of the city [Amaxiki] suffered important subsidence. Churches and nearly all the stone houses, as well as part of the fortress [of Ayia Mavra], collapsed. Fortunately, no fatalities were noted because the residents evacuated to open space as they were warned by a muffled and continuous clicking coming from the west, by a sea level rise, and by a wind storm. An observer counted 424 shocks occurring from the 31st of January to the 28th of March; six of them were very strong. The previous account leaves no doubt that the most violent and destructive earthquake of the 1820 seismic sequence was the one on 17 March (N.S.) not that on 21 February (N.S.), as other authors considered. The initial error can be found in the publication by, who, having in mind only a part of the above memory note, dated the earthquake as the 21st of February instead of the 17th of March.