Magnitude7.7

Reviewed by USGSAfghanistan118y ago

M7.7 earthquake 52 km ESE of Farkhār, Afghanistan

Wednesday, July 7, 1909, 21:37:51 UTC · 36.324°N, 70.357°E

A magnitude 7.7 earthquake struck 52 km ESE of Farkhār, Afghanistan on Wednesday, July 7, 1909, 21:37:51 UTC, at a depth of 200.0 km (intermediate). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude
7.7
Major · mw
Depth
200 km
Intermediate
Felt reports
0
Did You Feel It?
Est. shaking
VI
Strong (ShakeMap)
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

5.4 megatons of TNT

That is about 355 times the Hiroshima bomb. It released about 11,220 times the energy of a magnitude 5.0.

Tectonic setting

262 km

from the nearest mapped plate boundary, between the Eurasian and Indian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: intermediate

200 km

Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.

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 has not published any M2.5+ earthquake within 200 km in the 30 days after this event.

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 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 510 recorded deaths. The most severe:

  1. 1842

    Jalalabad

    19 Feb 1842 · 214 km away

    500 deathsSevere damage ($5–24M)

  2. 1909

    Pakistan

    8 Jul 1909 · 214 km away

    10 deathsLimited damage (under $1M)

  3. 1832

    Afghanistan

    22 Jan 1832 · 61 km away

    Severe damage ($5–24M)

  4. 1874

    Afghanistan

    18 Oct 1874 · 192 km away

    Severe damage ($5–24M)

  5. 1909M8.1

    Hindu-Kush

    7 Jul 1909 · 23 km away · intensity VII

  6. 1896M7.5

    Afghanistan

    23 Sep 1896 · 95 km away · intensity VI

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

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