Space-Time Analisis of Seismisity of the Territory of the Caucasus

Category Tectonic & Seismotectonic
Group GSI.IR
Location 4th internetional Conference on Seismology
Holding Date 11 March 2008
     The complex geological structure of Tavro-Caucasian region consisting of blocks and megablocks of various significance and their interaction under the tectonic strains brings to appropriate manifestations of seismic field, on dynamics, change of seismic activity, on the velocity of volumetric (longitudinal andtransversal) waves’ propagation and recurrence of weak earthquakes during preparation of strong ones. The data on earthquakes of Caucasus are inhomogeneous. With the development of the network of seismological observations in Caucasus the representability of earthquakes’ registration changed, therefore our researches were divided into stages. Are studied strong earthquakes with M 5,O of Caucasus with aftershock manifestation, and for the territory of Armenian plateau with M 4. Before the strong earthquakes were observed various anomalous variations in space-time distribution of more weak earthquakes. We calculated the values , where ni- current and - long average amount of earthquakes with M 2,4 .
For the beginning of anomalies the meaning -1 was accepted.Were observed the variations of characteristics of seismic activity AIO, its contrast in space, i.e. combination of seismic calm with activation. Was conducted space-time grouping of source zones and their remote interaction (after the Spitak destructive earthquake of 1988 occured earthquakes with M 6,5 on the territory of Turkey, Iran, Georgia etc). Before the strong earthquakes on the territory of Caucasus are observing "swars" of earthquakes. The energetic characteristics of the "swarm" is reminding about the strong earthquake which is preparing up to 5OO km ftom them Is observing migration of space densities of the sources of earthquakes. The most informative precursor for the territory of Caucasus is the value of the angular coefficient of the graph of recurrence was studied in space and time. Before the strong earthquakes is observed reduction of the value of the parameter y(b) . Is
studied the parameter - total released strain from the elementary area. The study of above mentioned parameters in space and time brought to the following conclusion: the earthquakes on the territory of Caucasus by the character of its manifestation are different Before the all strong earthquakes of Caucasus is identically observing the anomaly by angular coefficient of inclination of the graph of recurrence and background level of seismicity.

tags: etc