Reviewed by USGS22y ago
M3.4 earthquake in Ionian Sea
Tuesday, August 31, 2004, 09:03:20 UTC · 37.620°N, 20.990°E
A magnitude 3.4 earthquake struck in Ionian Sea on Tuesday, August 31, 2004, 09:03:20 UTC, at a depth of 9.0 km (shallow).
- Magnitude
- 3.4
- Minor · md
- Depth
- 9 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
2 tons of TNT
That is about 1/7,931 of the Hiroshima bomb. A magnitude 5.0 releases about 251 times more energy.
Tectonic setting
45 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: shallow
9 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 5 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M3.6 on September 8, 2004. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 3.230 km SSW of Lithakiá, Greece22y ago · 31 km SW of this epicenter
- 3.42 km SE of Kardamás, Greece22y ago · 36 km NE of this epicenter
- 3.310 km NE of Katastárion, Greece22y ago · 32 km N of this epicenter
- 3.658 km W of Filiatrá, Greece22y ago · 48 km S of this epicenter
- 3.538 km SW of Lithakiá, Greece22y ago · 43 km SW of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 469 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.9Southern GreeceAugust 11, 1903 · 254 km SE of this epicenter
- 7.34 km WNW of Koróni, GreeceOctober 6, 1947 · 122 km SE of this epicenter
- 7.026 km SW of Lixoúri, GreeceJanuary 17, 1983 · 81 km NW of this epicenter
- 6.815 km ENE of Póros, GreeceAugust 12, 1953 · 63 km N of this epicenter
- 6.86 km SW of Galaxídhion, GreeceMarch 31, 1965 · 142 km NE of this epicenter
- 6.7Ionian SeaNovember 15, 1959 · 45 km NW of this epicenter
- 6.75 km SW of Domvraína, GreeceFebruary 24, 1981 · 183 km E of this epicenter
- 6.77 km NE of Anávra, GreeceApril 30, 1954 · 206 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 149 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 5,682 recorded deaths. The most severe:
- 1750
Morea,Cerigo
7 Jun 1750 · 238 km away · intensity X
2,000 deaths
- 1953M7.2
Lixouri-Argostoli (Kephallenia)
12 Aug 1953 · 77 km away · intensity X
476 deaths$100 million damagetsunami
- 1820M6.9
Zakinthos (Zante)
29 Dec 1820 · 27 km away · intensity X
388 deathsSevere damage ($5–24M)tsunami
- 1886M6.8
Triphylie (Peleponese), Philiatra
27 Aug 1886 · 85 km away · intensity X
326 deathsSevere damage ($5–24M)tsunami
- 1767M6.7
Kefalonia
11 Jul 1767 · 86 km away · intensity X
303 deathsSevere damage ($5–24M)
- 1894M6.7
Locride, Malesina-Martinon (Lokris)
20 Apr 1894 · 222 km away · intensity X
255 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.