Reviewed by USGSGreece46y ago
M4.2 earthquake 15 km WNW of Kalávryta, Greece
Monday, March 23, 1981, 21:45:11 UTC · 38.105°N, 21.964°E
A magnitude 4.2 earthquake struck 15 km WNW of Kalávryta, Greece on Monday, March 23, 1981, 21:45:11 UTC, at a depth of 64.4 km (shallow).
- Magnitude
- 4.2
- Light · mb
- Depth
- 64 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
30 tons of TNT
That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.
Tectonic setting
30 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
64 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 M4.6 on April 14, 1981. 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 392 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.9Southern GreeceAugust 11, 1903 · 251 km S of this epicenter
- 7.34 km WNW of Koróni, GreeceOctober 6, 1947 · 144 km S of this epicenter
- 7.055 km S of Mýrina, GreeceFebruary 19, 1968 · 297 km NE of this epicenter
- 6.97 km NNE of Ágios Nikólaos, GreeceSeptember 26, 1932 · 289 km NE of this epicenter
- 6.815 km ENE of Póros, GreeceAugust 12, 1953 · 90 km W of this epicenter
- 6.86 km SW of Galaxídhion, GreeceMarch 31, 1965 · 41 km NE of this epicenter
- 6.7Ionian SeaNovember 15, 1959 · 126 km W of this epicenter
- 6.75 km SW of Domvraína, GreeceFebruary 24, 1981 · 86 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 136 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 5,643 recorded deaths. The most severe:
- 1750
Morea,Cerigo
7 Jun 1750 · 231 km away · intensity X
2,000 deaths
- 1953M7.2
Lixouri-Argostoli (Kephallenia)
12 Aug 1953 · 104 km away · intensity X
476 deaths$100 million damagetsunami
- 1820M6.9
Zakinthos (Zante)
29 Dec 1820 · 74 km away · intensity X
388 deathsSevere damage ($5–24M)tsunami
- 1886M6.8
Triphylie (Peleponese), Philiatra
27 Aug 1886 · 114 km away · intensity X
326 deathsSevere damage ($5–24M)tsunami
- 1767M6.7
Kefalonia
11 Jul 1767 · 132 km away · intensity X
303 deathsSevere damage ($5–24M)
- 1894M6.7
Locride, Malesina-Martinon (Lokris)
20 Apr 1894 · 121 km away · intensity X
255 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.