Seismic Hazards in Azerbaijan Informed by Geodesy

Researchers: F. Kadirov, A. Alizadeh, I. Guliev, Geology Institute, Azerbaijan National Academy of Sciences, Baku, Azerbaijan; M. Floyd, R. Reilinger, S. Kuleli, R. King, M. Nafi Toksoz, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.

Written by Linda Rowan
12 November 2013

Summary

Azerbaijan encompasses the eastern Kura basin and the Caucasus Mountains rising on its northern side. Historical, geological and seismological information details past large earthquakes and the potential for future seismic risk. Recent geodetic observations suggest a significant strain rate across the Kura basin that may be related to a series of faults that are locked. The higher strain rate may signify a greater seismic risk for Azerbaijan’s largest city, Baku and a nearby major petroleum pipeline.

Observations

The Arabia-Eurasian continental collision created the Caucasus Mountains and the collision zone near the Caspian Sea consists of 3 major fault systems. Contraction is occurring across this zone as the collision continues. Geodetic observations started in 1998 with more stations added until 2010. Data from 12 stations in Eastern Azerbaijan have been used to determine the strain rate across the colliding plates at the Kura basin.

Results

The strain accumulation at a rate of 15 millimeters per year across the Kura basin suggests a north-dipping thrust fault that is parallel to the Main Caucasus Thrust Fault and/or a right-lateral shear and convergence across a northwest-southeast striking extension of the Main Caucasus fault striking along the west coast of the Caspian Sea. These models suggest a significant seismic risk for the populated city of Baku and the energy-resource infrastructure near the city (for example, petroleum wells, offshore rigs and pipelines). A denser geodetic network and further study would help to determine better the earthquake risk and understand the complex geologic structure of this major plate boundary.