Magnitude5.0

Reviewed by USGSIran97y ago

M5.0 earthquake 28 km WNW of Ahar, Iran

Friday, May 9, 1930, 01:43:15 UTC · 38.618°N, 46.793°E

A magnitude 5.0 earthquake struck 28 km WNW of Ahar, Iran on Friday, May 9, 1930, 01:43:15 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M5.2 on May 8, 1930.

Magnitude
5.0
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 earthquakeDashed circle: 75 km aftershock search area

In context

How big was it, and why here?

Energy released

548 tons of TNT

That is about 1/28 of the Hiroshima bomb. Each whole step in magnitude is about 32 times more energy.

Tectonic setting

294 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 lists 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M5.1 on May 21, 1930. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M5.0
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.116 km SSE of Deste, Azerbaijan97y ago · 71 km W of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 15 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 187,906 recorded deaths. The most severe:

  1. 1727

    Tabriz

    18 Nov 1727 · 81 km away · intensity VIII

    77,000 deathsExtreme damage ($25M+)

  2. 1780M7.7

    Tabriz

    8 Jan 1780 · 86 km away · intensity IX

    50,000 deathsExtreme damage ($25M+)

  3. 1721M7.7

    Tabriz

    26 Apr 1721 · 80 km away

    40,000 deathsExtreme damage ($25M+)

  4. 1779M6.5

    Tabriz

    27 Dec 1779 · 69 km away · intensity VII

    10,000 deathsSevere damage ($5–24M)

  5. 1930M7.1

    Salmas

    6 May 1930 · 184 km away · intensity IX

    2,539 deathsExtreme damage ($25M+)

  6. 1902M6.9

    Semacha; N Iran

    13 Feb 1902 · 278 km away · intensity IX

    2,000 deathsExtreme damage ($25M+)

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

Nearby trackers

Closest city pages