Reviewed by USGSGreece104y ago
M6.4 earthquake 18 km S of Pefkochóri, Greece
Wednesday, December 5, 1923, 20:56:49 UTC · 39.820°N, 23.594°E
A magnitude 6.4 earthquake struck 18 km S of Pefkochóri, Greece on Wednesday, December 5, 1923, 20:56:49 UTC, at a depth of 10.0 km (shallow). It is the strongest earthquake within 300 km since an M6.6 on February 18, 1911.
- Magnitude
- 6.4
- Strong · mw
- Depth
- 10 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VI
- Strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
58 kilotons of TNT
That is about 4 times the Hiroshima bomb. It released about 122 times the energy of a magnitude 5.0.
Tectonic setting
20 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
10 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 has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 51 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.2Aegean SeaNovember 8, 1905 · 93 km E of this epicenter
- 7.07 km SE of Stara Kresna, BulgariaApril 4, 1904 · 217 km N of this epicenter
- 6.86 km W of Stara Kresna, BulgariaApril 4, 1904 · 224 km N of this epicenter
- 6.617 km NNW of Bilisht, AlbaniaFebruary 18, 1911 · 252 km NW of this epicenter
- 6.56 km N of Tríkeri, GreeceJanuary 20, 1905 · 86 km SW of this epicenter
- 6.326 km NNW of Itháki, GreeceNovember 27, 1914 · 293 km SW of this epicenter
- 6.21 km SW of Avlónas, GreeceOctober 17, 1914 · 176 km S of this epicenter
- 6.115 km NE of Bobov Dol, BulgariaOctober 8, 1905 · 296 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 80 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 24,437 recorded deaths. The most severe:
- 1883M7.3
Ayvalik, Izmir, Cesme
15 Oct 1883 · 281 km away · intensity X
15,000 deathsExtreme damage ($25M+)
- 1881M7.3
Khios; Turkey: Cesme
3 Apr 1881 · 288 km away · intensity XI
7,866 deathsExtreme damage ($25M+)tsunami
- 1867M7.0
Mitilini; Turkey: Izmir
7 Mar 1867 · 250 km away
563 deathsSevere damage ($5–24M)tsunami
- 1894M6.7
Locride, Malesina-Martinon (Lokris)
20 Apr 1894 · 140 km away · intensity X
255 deathsSevere damage ($5–24M)
- 1817M6.6
Achaia: Aeghion
23 Aug 1817 · 210 km away · intensity X
128 deathsSevere damage ($5–24M)tsunami
- 1870M7.5
Greece
30 Sep 1870 · 174 km away
100 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.