Turkey earthquakes

M5.9 earthquake 4 km SE of Köseköy, Turkey

A magnitude 5.9 earthquake struck 4 km SE of Köseköy, Turkey on Mon, Sep 13, 1999, 2:55 PM GMT+3 (11:55 UTC), 13 km (8 mi) below the surface.

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Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude: 5.9 (Mwb, body-wave moment), moderate
Magnitude from: USGS National Earthquake Information Center
Local time: Mon, Sep 13, 1999, 2:55 PM GMT+3
UTC: 1999-09-13 11:55:28 UTC
Depth: 13.0 km (8.1 mi), shallow
Epicenter: 40.709° N, 30.045° E
Region: Turkey
Strongest shaking: VIII, severe shaking
Tsunami flag: No
Status: Reviewed by a seismologist

Magnitude estimates

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
5.9	Mwb, body-wave moment	USGS National Earthquake Information Center	Preferred · Reviewed
5.79	Mw, moment	ISC-GEM global catalog	Final · ±0.1
5.8	Mwc, centroid moment	Global CMT project	Preliminary
5.72	Me, energy	Choy, USGS energy magnitude	Reviewed

Deaths and damage

From NOAA NCEI’s Significant Earthquake Database (record 5533), matched to this event by time and place.

Deaths: 7
Injuries: 422
Damage: Limited (under about $1 million)

Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.

NOAA’s full record of this earthquake

What happened

The USGS’s account of the effects of this earthquake.

Six people killed, one died of a heart attack, 422 injured and additional damage in the Adapazari-Golcuk-Kocaeli area. Felt in much of northwestern Turkey.

From the USGS event page for usp0009ede. U.S. Geological Survey text and figures are in the public domain.

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated: VIII, severe shaking
Peak ground acceleration: 49.9% of gravity
Peak ground velocity: 4.0 cm/s
Map: Automatic

USGS ShakeMap: estimated shaking intensity around the epicenter — Estimated shaking intensity. Map: USGS ShakeMap.

Did you feel it?

No one has reported feeling this quake to the USGS.

Fault motion and ground failure

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Faulting: Strike-slip
Nodal plane 1: Strike 268°, dip 59°, rake -176°
Nodal plane 2: Strike 176°, dip 86°, rake -31°

How well it is located

Reviewed by a seismologist.

Depth from: OPERATOR_ASSIGNED

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nearby

Within 100 km, magnitude 2.9 and up: 48 in the 60 days after this one and 108 in the 30 days before it.

After

Before

Earthquakes today Turkey earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event usp0009ede (also filed as choy19990913115528, gcmtb091399b, gcmt19990913115528, atlas19990913115529, iscgem1655942). Read Fri, Oct 2, 2026, 11:11 PM UTC.