Reviewed by USGSTurkey78y ago
M6.8 earthquake 14 km ENE of Yedisu, Turkey
Wednesday, August 17, 1949, 18:44:17 UTC · 39.503°N, 40.671°E
A magnitude 6.8 earthquake struck 14 km ENE of Yedisu, Turkey on Wednesday, August 17, 1949, 18:44:17 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.8 on December 26, 1939.
- Magnitude
- 6.8
- Strong · 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 earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
223 kilotons of TNT
That is about 15 times the Hiroshima bomb. It released about 468 times the energy of a magnitude 5.0.
Tectonic setting
21 km
from the nearest mapped plate boundary, between the Anatolian and Eurasian 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 100 km
USGS lists 2 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M5.5 on August 17, 1949. 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 47 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.820 km NNE of Erzincan, TurkeyDecember 26, 1939 · 103 km NW of this epicenter
- 7.018 km W of Doğanşar, TurkeyJanuary 24, 1916 · 297 km W of this epicenter
- 6.918 km ESE of Pasinler, TurkeySeptember 13, 1924 · 114 km NE of this epicenter
- 6.813 km NNE of Sincik, TurkeyDecember 4, 1905 · 231 km SW of this epicenter
- 6.326 km ENE of Koyulhisar, TurkeyFebruary 9, 1909 · 241 km NW of this epicenter
- 6.3TurkeyMay 18, 1929 · 236 km W of this epicenter
- 6.028 km E of Kars, TurkeyMay 1, 1935 · 262 km NE of this epicenter
- 6.04 km NNE of Erzincan, TurkeyNovember 12, 1941 · 104 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 37 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 61,414 recorded deaths. The most severe:
- 1939M7.8
Erzincan
26 Dec 1939 · 103 km away · intensity XII
32,700 deaths$20 million damagetsunami
- 1859M6.1
Erzurum
2 Jun 1859 · 70 km away
15,000 deathsSevere damage ($5–24M)
- 1784
Erzurum,Erzincan
23 Jul 1784 · 103 km away
5,000 deathsSevere damage ($5–24M)
- 1903M6.3
Malazgirt
28 Apr 1903 · 164 km away · intensity X
3,560 deathsExtreme damage ($25M+)
- 1903M5.8
Varginis,Cardahli,Mehkerek
28 May 1903 · 232 km away · intensity VIII
1,000 deathsSevere damage ($5–24M)
- 1946M5.9
Ustukran
31 May 1946 · 68 km away · intensity VIII
840 deathsModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.