M7.1 earthquake 10 km SSW of Salmās, Iran

Tuesday, May 6, 1930, 22:34:27 UTC · 38.108°N, 44.727°E

A magnitude 7.1 earthquake struck 10 km SSW of Salmās, Iran on Tuesday, May 6, 1930, 22:34:27 UTC, at a depth of 15.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude: 7.1; Major · mw
Depth: 15 km; Shallow
Felt reports: 0; Did You Feel It?
Est. shaking: VIII; Severe (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

674 kilotons of TNT

That is about 45 times the Hiroshima bomb. It released about 1,413 times the energy of a magnitude 5.0.

Tectonic setting

122 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 200 km

USGS lists 12 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.2 on May 8, 1930. 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 8 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 29 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 188,813 recorded deaths. The most severe:

1727
Tabriz
18 Nov 1727 · 138 km away · intensity VIII
77,000 deathsExtreme damage ($25M+)
1780M7.7
Tabriz
8 Jan 1780 · 130 km away · intensity IX
50,000 deathsExtreme damage ($25M+)
1721M7.7
Tabriz
26 Apr 1721 · 174 km away
40,000 deathsExtreme damage ($25M+)
1779M6.5
Tabriz
27 Dec 1779 · 173 km away · intensity VII
10,000 deathsSevere damage ($5–24M)
1903M6.3
Malazgirt
28 Apr 1903 · 223 km away · intensity X
3,560 deathsExtreme damage ($25M+)
1930M7.1
Salmas
6 May 1930 · 6 km away · intensity IX
2,539 deathsExtreme damage ($25M+)

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

Nearby trackers