SEISMICITY

Azerbaijan saw devastating earthquakes since the ancient times. The first reports on "an overall devastating event that destroyed all towns and villages" is dated back to 427 AD. In 1139 AD, a devastating earthquake with the magnitude of IX took place in Azerbaijan. The town of Ganja was destroyed completely and gross casualties were reported. It is noteworthy that Goygol Lake had been generated as a result of that same earthquake.

In the 19th century, Shamahy town suffered several devastating earthquakes. Several of them that occurred in 1856, 1861, and1872 and 1902 that are considered to be the strongest and devastating were estimated as strong as VII and X points of magnitude.

The first seismic station in Azerbaijan Republic was established soon after 1902 in Baku by E. Nobel. Afterwards seismic stations were set in different areas in Azerbaijan (Balakhany, Zurnabad, Shamahy, Ganja, Nakhchivan, Lancaran, Chilov Island, and Mingechevir). 14 analog seismic stations were monitored earthquakes in Azerbaijan. Starting from 2003 earthquakes in Azerbaijan have been monitored and still continued by means of digital "Kinemetrix" system (that includes 14 station) set according to the nation-wide leader Heydar Aliyev's decree. Acquired data is transmitted through satellite communication system operating in real time domain.

Seismic event monitoring by means of installed equipment has been carried out since last century's 50-s. Since the beginning such kind of observations applied analog equipment using photo-recording system. Those systems were replaced by proprietary made magnetometer Mobill ACC station designed at ad hoc Design Laboratory established at the Institute of Geology, ANAS. Since 1996 precision seismology observations has been curried out using digital ISS telemetric system (manufactured in South Africa). In 2003 Institute of geology, ANAS established Seismic Monitoring and Geodynamic Center supported by Civil Investigations and Development Fond. The Center was equipped with eight modified mobile digital ISS stations.

Tangible earthquake seismic effects have studied by R. Aghamirzayev, S. Aliyeva, A. Hasanav, E. Gul, R. Jafarov, V. Kuznetsov, R. Shafadiyayev et al that enable to identify earthquakes key parameters, and to study their activity attenuation.

Earthquake triggering mechanism studies carried out by A. Agalarova and S. Aghayeva within onshore and offshore Azerbaijan areas have subjected to severe and intricate strain. It was recognized that earthquake focuses are located within earth crust and about 90% of them are associated with sedimentary rocks. Seismicity quantitative and recurrence frequency analysis demonstrates significant seismic activity throughout Azerbaijan territory. Moreover, future earthquake events are expected to be moderate in terms of released energy.

Maps of Azerbaijan territory seismicity ranking on a scale 1:500,000 has been compiled since 1937. State seismicity ranking maps have been compiled and approved by Institute of Geology, ANAS in 1963, 1967, 1979 and 1989. Background seismicity rate shown on 1989 seismicity map is accepted as much as VII point of magnitude. IX point magnitude earthquake areas cover Great Caucasus Balacan-Shamahy zone including both Ganja and Nakhchivan areas, and actually covers Minor Caucasus too. Seismicity ranking maps bears overview feature and therefore cannot be used as a reference guide for the earthquake-durable building construction projects.