Reviewed by USGSGreece22y ago
M2.5 earthquake 9 km SSE of Ágioi Theódoroi, Greece
Friday, July 23, 2004, 22:08:20 UTC · 37.850°N, 23.190°E
A magnitude 2.5 earthquake struck 9 km SSE of Ágioi Theódoroi, Greece on Friday, July 23, 2004, 22:08:20 UTC, at a depth of 5.0 km (shallow).
- Magnitude
- 2.5
- Minor · md
- Depth
- 5 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: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
85 kg of TNT
That is about 1/177,558 of the Hiroshima bomb. A magnitude 5.0 releases about 5,623 times more energy.
Tectonic setting
62 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
5 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 50 km
USGS lists 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M3.3 on July 28, 2004. 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 525 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.9Southern GreeceAugust 11, 1903 · 206 km S of this epicenter
- 7.719 km SSE of Amorgós, GreeceJuly 9, 1956 · 278 km SE of this epicenter
- 7.34 km WNW of Koróni, GreeceOctober 6, 1947 · 162 km SW of this epicenter
- 7.2Aegean SeaNovember 8, 1905 · 279 km NE of this epicenter
- 7.261 km W of Eresós, GreeceDecember 19, 1981 · 235 km NE of this epicenter
- 7.026 km SW of Lixoúri, GreeceJanuary 17, 1983 · 260 km W of this epicenter
- 7.055 km S of Mýrina, GreeceFebruary 19, 1968 · 230 km NE of this epicenter
- 6.97 km NNE of Ágios Nikólaos, GreeceSeptember 26, 1932 · 278 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 161 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 28,359 recorded deaths. The most severe:
- 1883M7.3
Ayvalik, Izmir, Cesme
15 Oct 1883 · 268 km away · intensity X
15,000 deathsExtreme damage ($25M+)
- 1881M7.3
Khios; Turkey: Cesme
3 Apr 1881 · 272 km away · intensity XI
7,866 deathsExtreme damage ($25M+)tsunami
- 1750
Morea,Cerigo
7 Jun 1750 · 184 km away · intensity X
2,000 deaths
- 1953M7.2
Lixouri-Argostoli (Kephallenia)
12 Aug 1953 · 215 km away · intensity X
476 deaths$100 million damagetsunami
- 1820M6.9
Zakinthos (Zante)
29 Dec 1820 · 171 km away · intensity X
388 deathsSevere damage ($5–24M)tsunami
- 1886M6.8
Triphylie (Peleponese), Philiatra
27 Aug 1886 · 156 km away · intensity X
326 deathsSevere damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.