Magnitude7.3

Reviewed by USGSGreece80y ago

M7.3 earthquake 4 km WNW of Koróni, Greece

Monday, October 6, 1947, 19:55:37 UTC · 36.808°N, 21.916°E

A magnitude 7.3 earthquake struck 4 km WNW of Koróni, Greece on Monday, October 6, 1947, 19:55:37 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.9 on August 11, 1903.

Magnitude
7.3
Major · mw
Depth
15 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
VII
Very 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

1.3 megatons of TNT

That is about 89 times the Hiroshima bomb. It released about 2,818 times the energy of a magnitude 5.0.

Tectonic setting

55 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

15 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 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 128 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

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 4,429 recorded deaths. The most severe:

  1. 1750

    Morea,Cerigo

    7 Jun 1750 · 118 km away · intensity X

    2,000 deaths

  2. 1820M6.9

    Zakinthos (Zante)

    29 Dec 1820 · 120 km away · intensity X

    388 deathsSevere damage ($5–24M)tsunami

  3. 1886M6.8

    Triphylie (Peleponese), Philiatra

    27 Aug 1886 · 38 km away · intensity X

    326 deathsSevere damage ($5–24M)tsunami

  4. 1767M6.7

    Kefalonia

    11 Jul 1767 · 207 km away · intensity X

    303 deathsSevere damage ($5–24M)

  5. 1894M6.7

    Locride, Malesina-Martinon (Lokris)

    20 Apr 1894 · 229 km away · intensity X

    255 deathsSevere damage ($5–24M)

  6. 1867M7.2

    Cephalonia

    4 Feb 1867 · 206 km away · intensity X

    223 deathsSevere damage ($5–24M)tsunami

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers

Closest city pages