Reviewed by USGSGreece99y ago
M6.3 earthquake 2 km NW of Sofikón, Greece
Sunday, April 22, 1928, 20:13:54 UTC · 37.811°N, 23.033°E
A magnitude 6.3 earthquake struck 2 km NW of Sofikón, Greece on Sunday, April 22, 1928, 20:13:54 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.3 on July 1, 1927.
- Magnitude
- 6.3
- Strong · mw
- Depth
- 15 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 100 km aftershock search area
In context
How big was it, and why here?
Energy released
43 kilotons of TNT
That is about 3 times the Hiroshima bomb. It released about 89 times the energy of a magnitude 5.0.
Tectonic setting
57 km
from the nearest mapped plate boundary, between the Aegean Sea and Eurasian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
15 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 100 km
USGS lists 2 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M5.5 on April 29, 1928. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 67 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.9Southern GreeceAugust 11, 1903 · 201 km S of this epicenter
- 7.2Aegean SeaNovember 8, 1905 · 289 km NE of this epicenter
- 6.56 km N of Tríkeri, GreeceJanuary 20, 1905 · 150 km N of this epicenter
- 6.532 km NNW of Lixoúri, GreeceAugust 7, 1915 · 245 km W of this epicenter
- 6.521 km SW of Lixoúri, GreeceJanuary 27, 1915 · 244 km W of this epicenter
- 6.411 km W of Kyllíni, GreeceJanuary 24, 1912 · 178 km W of this epicenter
- 6.418 km S of Pefkochóri, GreeceDecember 5, 1923 · 229 km N of this epicenter
- 6.334 km NW of Itháki, GreeceAugust 10, 1915 · 243 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 92 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 27,383 recorded deaths. The most severe:
- 1883M7.3
Ayvalik, Izmir, Cesme
15 Oct 1883 · 283 km away · intensity X
15,000 deathsExtreme damage ($25M+)
- 1881M7.3
Khios; Turkey: Cesme
3 Apr 1881 · 286 km away · intensity XI
7,866 deathsExtreme damage ($25M+)tsunami
- 1750
Morea,Cerigo
7 Jun 1750 · 179 km away · intensity X
2,000 deaths
- 1820M6.9
Zakinthos (Zante)
29 Dec 1820 · 157 km away · intensity X
388 deathsSevere damage ($5–24M)tsunami
- 1886M6.8
Triphylie (Peleponese), Philiatra
27 Aug 1886 · 142 km away · intensity X
326 deathsSevere damage ($5–24M)tsunami
- 1767M6.7
Kefalonia
11 Jul 1767 · 231 km away · intensity X
303 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.