Reviewed by USGS124y ago
M7.9 earthquake in Southern Greece
Tuesday, August 11, 1903, 04:33:35 UTC · 36.000°N, 23.000°E
A magnitude 7.9 earthquake struck in Southern Greece on Tuesday, August 11, 1903, 04:33:35 UTC, at a depth of 80.0 km (intermediate). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 7.9
- Major · ms
- Depth
- 80 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
In context
How big was it, and why here?
Energy released
11 megatons of TNT
That is about 709 times the Hiroshima bomb. It released about 22,387 times the energy of a magnitude 5.0.
Tectonic setting
57 km
from the nearest mapped plate boundary, between the Aegean Sea and African plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
80 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 200 km
USGS has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists no earlier M5.0+ earthquakes within 300 km.
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 50 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 7,273 recorded deaths. The most severe:
- 1810
Crete: Iraklion (Candia)
16 Feb 1810 · 189 km away · intensity X
3,000 deathsSevere damage ($5–24M)tsunami
- 1750
Morea,Cerigo
7 Jun 1750 · 22 km away · intensity X
2,000 deaths
- 1856
Crete; Egypt
12 Oct 1856 · 276 km away · intensity XI
600 deathsSevere damage ($5–24M)tsunami
- 1820M6.9
Zakinthos (Zante)
29 Dec 1820 · 249 km away · intensity X
388 deathsSevere damage ($5–24M)tsunami
- 1886M6.8
Triphylie (Peleponese), Philiatra
27 Aug 1886 · 169 km away · intensity X
326 deathsSevere damage ($5–24M)tsunami
- 1894M6.7
Locride, Malesina-Martinon (Lokris)
20 Apr 1894 · 290 km away · intensity X
255 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.