M7.1 earthquake 13 km SSW of Düzce, Turkey

Sunday, May 26, 1957, 06:33:37 UTC · 40.730°N, 31.090°E

A magnitude 7.1 earthquake struck 13 km SSW of Düzce, Turkey on Sunday, May 26, 1957, 06:33:37 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M7.3 on March 18, 1953.

Magnitude: 7.1; Major · mw
Depth: 25 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

651 kilotons of TNT

That is about 43 times the Hiroshima bomb. It released about 1,365 times the energy of a magnitude 5.0.

Tectonic setting

13 km

from the nearest mapped plate boundary, between the Anatolian and Eurasian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

25 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 7 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.0 on May 26, 1957. 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 80 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 34 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 27,721 recorded deaths. The most severe:

1719
Turkey
25 May 1719 · 143 km away · intensity X
6,000 deathsExtreme damage ($25M+)
1943M7.5
Ladik, Samsun, Havza
26 Nov 1943 · 216 km away · intensity XI
4,020 deathsExtreme damage ($25M+)
1766M6.5
Turkey
22 May 1766 · 176 km away · intensity X
4,000 deathsExtreme damage ($25M+)tsunami
1944M7.6
Turkey
1 Feb 1944 · 161 km away · intensity X
2,381 deathsSevere damage ($5–24M)
1855M6.7
Tayabas, Bursa
28 Feb 1855 · 178 km away · intensity X
2,200 deathsSevere damage ($5–24M)
1754M6.8
Izmit
2 Sep 1754 · 159 km away · intensity IX
2,000 deathsExtreme damage ($25M+)tsunami

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

Nearby trackers