Reviewed by USGSGreece48y ago
M3.6 earthquake 11 km NNE of Néa Apollonía, Greece
Monday, August 21, 1978, 00:52:45 UTC · 40.711°N, 23.510°E
A magnitude 3.6 earthquake struck 11 km NNE of Néa Apollonía, Greece on Monday, August 21, 1978, 00:52:45 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 3.6
- 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
4 tons of TNT
That is about 1/3,975 of the Hiroshima bomb. A magnitude 5.0 releases about 126 times more energy.
Tectonic setting
97 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
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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.1 on September 3, 1978. 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 261 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.2Aegean SeaNovember 8, 1905 · 117 km SE of this epicenter
- 7.19 km S of Stara Zagora, BulgariaApril 14, 1928 · 254 km NE of this epicenter
- 7.13 km W of Brezovo, BulgariaApril 18, 1928 · 223 km NE of this epicenter
- 7.07 km SE of Stara Kresna, BulgariaApril 4, 1904 · 118 km N of this epicenter
- 7.055 km S of Mýrina, GreeceFebruary 19, 1968 · 193 km SE of this epicenter
- 6.97 km NNE of Ágios Nikólaos, GreeceSeptember 26, 1932 · 49 km SE of this epicenter
- 6.86 km W of Stara Kresna, BulgariaApril 4, 1904 · 126 km N of this epicenter
- 6.86 km SW of Galaxídhion, GreeceMarch 31, 1965 · 283 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 87 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 3,094 recorded deaths. The most severe:
- 1963M6.0
Macedonia: Skopje
26 Jul 1963 · 240 km away · intensity X
1,070 deaths$1.0 billion damage
- 1867M7.0
Mitilini; Turkey: Izmir
7 Mar 1867 · 298 km away
563 deathsSevere damage ($5–24M)tsunami
- 1894M6.7
Locride, Malesina-Martinon (Lokris)
20 Apr 1894 · 236 km away · intensity X
255 deathsSevere damage ($5–24M)
- 1932M6.9
Hierissos-Strantonion (Chalkidiki)
26 Sep 1932 · 40 km away · intensity X
161 deathsExtreme damage ($25M+)tsunami
- 1817M6.6
Achaia: Aeghion
23 Aug 1817 · 294 km away · intensity X
128 deathsSevere damage ($5–24M)tsunami
- 1928M6.8
Chirpan
14 Apr 1928 · 223 km away · intensity X
127 deathsExtreme damage ($25M+)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.