Reviewed by USGSIran96y ago
M5.5 earthquake 9 km NNE of Marand, Iran
Tuesday, May 12, 1931, 10:25:13 UTC · 38.508°N, 45.820°E
A magnitude 5.5 earthquake struck 9 km NNE of Marand, Iran on Tuesday, May 12, 1931, 10:25:13 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.4 on April 27, 1931.
- Magnitude
- 5.5
- Moderate · mw
- Depth
- 15 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 earthquake
In context
How big was it, and why here?
Energy released
3 kilotons of TNT
That is about 1/5 of the Hiroshima bomb. It released about 6 times the energy of a magnitude 5.0.
Tectonic setting
221 km
from the nearest mapped plate boundary, between the Eurasian and Arabian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
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 75 km
USGS has not published any M2.5+ earthquake within 75 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 27 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.110 km SSW of Salmās, IranMay 6, 1930 · 105 km SW of this epicenter
- 6.414 km S of Hats’avan, ArmeniaApril 27, 1931 · 93 km N of this epicenter
- 6.213 km SE of Khowy, IranMay 8, 1930 · 67 km W of this epicenter
- 6.015 km NE of Prishibinskoye, AzerbaijanFebruary 19, 1924 · 265 km E of this epicenter
- 5.78 km N of Başkale, TurkeyApril 25, 1918 · 165 km W of this epicenter
- 5.711 km NW of Ahlat, TurkeyJanuary 27, 1913 · 300 km W of this epicenter
- 5.717 km NNW of Salmās, IranMay 29, 1930 · 103 km W of this epicenter
- 5.629 km SE of Khowy, IranJune 4, 1930 · 61 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 29 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 192,283 recorded deaths. The most severe:
- 1727
Tabriz
18 Nov 1727 · 70 km away · intensity VIII
77,000 deathsExtreme damage ($25M+)
- 1780M7.7
Tabriz
8 Jan 1780 · 66 km away · intensity IX
50,000 deathsExtreme damage ($25M+)
- 1721M7.7
Tabriz
26 Apr 1721 · 102 km away
40,000 deathsExtreme damage ($25M+)
- 1779M6.5
Tabriz
27 Dec 1779 · 95 km away · intensity VII
10,000 deathsSevere damage ($5–24M)
- 1903M6.3
Malazgirt
28 Apr 1903 · 295 km away · intensity X
3,560 deathsExtreme damage ($25M+)
- 1931M6.3
Zangezur, Nakhitchevan
27 Apr 1931 · 79 km away · intensity VIII
2,890 deathsExtreme damage ($25M+)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.