TECTONIC SETTING OF THE IZMIT EARTHQUAKE - IPGP 

Version française 

See also Duzce earthquake page.

Westward escape of Anatolia-Aegea block between the North (dextral) and East (sinistral) Anatolian Faults. Current motion relative to Eurasia (GPS and SLR velocity vectors, in mm/yr, from Reilinger et al., 1997). Geological studies over a longer time period (holocene) indicate a slip rate of 2.5 cm/year on the North Anatolian Fault (Hubert, 1998).
The Izmit earthquake broke a 130 km long section of the North Anatolian fault

Map from Armijo et al., 1999

 
Detailed version of this map (GIF, 180 Ko) , other version with the Athens 7/9/99 quake (caption in french)

 

The North Anatolian Fault splays westward into two main branches, NAF(N) and NAF (S), 100 km apart. The Northern branch (N) bounds the southern side of the Gulf of Izmit, outlines the Marmara pull apart basin, cuts the Dardanelles structure, and marks the southern side of the Saros Gulf. The Izmit earthquake occurred on that branch, east of the Marmara Sea.

Map from Armijo et al., 1999
Fault plane solution from USGS and Harvard
 

 
Detailed version of this map (JPEG, 240 Ko)

A simplified sketch of the pull apart (captions in french, GIF, 120Ko)


SURFACE RUPTURES DUE TO IZMIT EARTHQUAKE

  New version, updated, of rupture map on Duzce earthquake page.

Preliminary report of fault segments with surface breaks

Western segment:  IPGP  (R. Armijo, B. Meyer, J. B. de Chabalier).
Central segment: ITU  (A. Barka, S. Akyuz, E. Altunel, Z. Cakir, G. Sunal, A. Dikbas, M. zkaya, B. Yerli).
Eastern segments: USGS (T. Fumal, R. Langridge, H. Stenner, S. Christofferson); SCEC (T. Rockwell, J. Dolan,T. Dawson, R. Hartleb,  A. Tucker)

Coordination by Aykut Barka. 


Older version without offsets (JPEG, 300 Ko)

13/9/99 - strong aftershock (M5.8): map of surface breaks with localization of the main shock and of this aftershock
 
 

Comparison of SPOT scenes taken before and after the earthquake. Areas under water appear in blue. 
 

© CNES - Spot Image  -   CNRS/INSU - IPGP 
(Traitement IPGP, B. Meyer - R. Lacassin) 


HOW THE NORTH ANATOLIAN FAULT WORKS:

Where? Why? Some mechanics... Izmit's earthquake mechanics (IPGP)


References: papers about active tectonics in Turkey and Greece


Other Links:

IPGP Département de Sismologie - Sismicité récente

IPGP Geoscope

IZMIT EARTHQUAKE (KOERI Turquie)  ou site mirroir (US):   IZMIT EARTHQUAKE

Kandili Observatory and Earthquake research institute (Turquie)

USGS Expedition to Turkey - 1999

SCEC report (field observations in Turkey)

HARVARD Seismology



 
R. LACASSIN et B. MEYER  - Laboratoire de Tectonique, Mécanique de la Lithosphère; CNRS - IPGP
Novembre 1999