Magnitude5.5

Reviewed by USGSCyprus106y ago

M5.5 earthquake 0 km ENE of Mórfou, Cyprus

Wednesday, April 20, 1921, 16:04:27 UTC · 35.200°N, 32.997°E

A magnitude 5.5 earthquake struck 0 km ENE of Mórfou, Cyprus on Wednesday, April 20, 1921, 16:04:27 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.4 on September 29, 1918.

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

94 km

from the nearest mapped plate boundary, between the Anatolian and African 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 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 1 M5.0+ earthquake 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 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 21,700 recorded deaths. The most severe:

  1. 1822

    Antakya; Syria: Halab,Dimashq (Damascus);

    13 Aug 1822 · 286 km away · intensity XI

    20,000 deathsExtreme damage ($25M+)tsunami

  2. 1796

    Al-Ladhiqiyah (Latakia)

    26 Feb 1796 · 255 km away · intensity IX

    1,500 deathsSevere damage ($5–24M)

  3. 1735

    Nicosia

    10 Apr 1735 · 37 km away · intensity IX

    200 deathsSevere damage ($5–24M)

  4. 1822

    Dimashq (Damascus), Halab; Cyprus

    5 Sep 1822 · 286 km away · intensity XI

    Extreme damage ($25M+)

  5. 1743

    Turkey

    14 Mar 1743 · 279 km away

    Moderate damage ($1–5M)tsunami

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

Nearby trackers

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