M3.9 earthquake 9 km ENE of Kolchikón, Greece

Thursday, July 13, 1978, 17:26:57 UTC · 40.793°N, 23.232°E

A magnitude 3.9 earthquake struck 9 km ENE of Kolchikón, Greece on Thursday, July 13, 1978, 17:26:57 UTC, at a depth of 10.0 km (shallow).

Magnitude: 3.9; Minor · mb
Depth: 10 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

11 tons of TNT

That is about 1/1,410 of the Hiroshima bomb. A magnitude 5.0 releases about 45 times more energy.

Tectonic setting

116 km

from the nearest mapped plate boundary, between the Aegean Sea and Eurasian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: shallow

10 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 7 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M3.8 on July 15, 1978. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 278 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 92 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 5,124 recorded deaths. The most severe:

1851M6.6
Vlore (Valona),Berat; Turkey
12 Oct 1851 · 300 km away · intensity XI
2,000 deathsExtreme damage ($25M+)tsunami
1963M6.0
Macedonia: Skopje
26 Jul 1963 · 217 km away · intensity X
1,070 deaths$1.0 billion damage
1851
Berat
17 Oct 1851 · 300 km away · intensity X
400 deathsSevere damage ($5–24M)
1894M6.7
Locride, Malesina-Martinon (Lokris)
20 Apr 1894 · 244 km away · intensity X
255 deathsSevere damage ($5–24M)
1920M6.2
Tepelene, Dragoti, Peshtani, Maricaj
26 Nov 1920 · 281 km away · intensity XI
200 deathsSevere damage ($5–24M)
1932M6.9
Hierissos-Strantonion (Chalkidiki)
26 Sep 1932 · 65 km away · intensity X
161 deathsExtreme damage ($25M+)tsunami

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

Nearby trackers