Seismicity of Ukraine

Scale 1:5 000 000

             Authors: Kendzera  О.V., Pustovitenko B.G., Kutas V.V., Kulchitsky V.E. Verbytsky S.T., Pronishin R.S., Safronov О.M.,  Korolyov V.О.,  Kalitova І.А., Pasynkov  G.D.,  Stasyuk А.F.

Seismicity of Ukraine becomes apparent in western, southwestern and southern areas, where two basic seismic regions are allocated: Carpathian and Crimean-Black Sea.

Seismicity of the Carpathian region is defined by earthquakes with fires in Zakarpattya, Carpathians, Prykarpattya and also in the nearby territories of neighbouring countries: Poland, Slovakia, Hungary and Romania. The most seismoactive is Zakarpattya.

In the western areas of Ukraine (from the XVІІ centuries up to our time) earthquakes are generally characterised by th depths of fires (h) 2-10 km and magnitudes (M) <5.5. Due to the small depth these earthquakes cause local vibrations of soil surfaces with intensity of 7-7.5 points. The same vibrations are felt in Zakarpattya due to the earthquakes deeper (h=35 km) and bigger in size (М=6.8) with fires located in Romania (Pishkolz) at the distance of about 60 km from the Ukrainian borders. In Prykarpattya the biggest authentically described earthquake took place in 1875 near the region Velyki Mosty (in the Lvov region). It was characterised by the magnitude М=5.3, fire's depth of h=19 km and was felt in the epicentral zone with the intensity of 6 points.

A considerable part of the Ukrainian territory is under influence of the undercrust earthquakes, which take place in the Vranch zone in Romania (area of the joint between the Eastern and Southern Carpathians). Fires of the earthquakes, which are capable to become the reason of macroseismic manifestations on the territory of Ukraine, are located in the mantle at depths ranging from 80 to 190 km. Maximum magnitudes of earthquakes in this zone reached 7.6 points. Due to the big depths and magnitudes, earthquakes of the Vranch zone become apperent on the huge territory: from the South of Greece to the North of Finland.

On the epicentres' map the earthquakes’ fires in the Vranch zone are presented since XІ century with magnitudes over 3.5 points. Isoseists of the strongest earthquakes in the Vranch zone are reliably established for the last two centuries. For the construction of isoseists the published materials were used, and for the earthquakes of 1977-1990 - authors' data.

Seismicity of the Crimean-Black Sea region is defined by the epicentres of the earthquakes located in the water area of the Black sea, near the Southern coast of Crimea which are characterised by the highest indicators throughout the Ukrainian territory: magnitudes up to 6.8. On the epicentres' map the Crimean earthquakes are presented with magnitudes, exceeding 2.0, during supervision period between the І century BC up to the present time. On the flat part of Crimea and the Sea of Azov fires of earthquakes with magnitudes over 1.0 are shown.

It is possible to consider the delta of Danube as separate seismic area. Here throughout the historical times earthquakes with maximum magnitude of about 7 points took place, which together with Vranch earthquakes' zone represent serious danger to the territory of Odessa region.

In the central part of Ukraine, in particular within the Ukrainian board, for the last centuries only several earthquakes with small depths (5-10 km) and low magnitudes (M = 3) were authentically fixed. These earthquakes had local character of seismic influence. The strongest earthquake in the Eastern part of Ukraine is considered to be the one in 1913 near Kupyansk (magnitude 3.5, local vibrations with the intensity up to 5-6 points). In the western part of Ukraine, near urban village Mykulynzi in the Ternopil region, earthquake with magnitude of 4 took place on January 3rd, 2002, and had intensity of 6 points in the epicentre with 7 points' effects on the weakened soils. Heretofore the specified territory had indicator of 5 points.

In Ukraine the national network of seismic supervision was created, with 18 seismic and 14 complex geophysical stations. The oldest is the seismic station "Lviv" which was founded in 1899. Digital seismic station "Kiev" was created in 1994 and it is a part of the Global seismic network.