| Title | SOURCE MECHANISM AND SIZE OF THE 24 APRIL 2002 ML 5.2 GNJILANE (KOSOVO) EARTHQUAKE |
| Author/s | Vera Čejkovska, Lazo Pekevski, Dragana Černih |
| Citation | V. Čejkovska, L. Pekevski and D. Černih, "SOURCE MECHANISM AND SIZE OF THE 24 APRIL 2002 ML 5.2 GNJILANE (KOSOVO) EARTHQUAKE", Contributions, Sec. Math. Tech. Sci., MASA, ISSN 0351–3246, Vol. 32, no.1-2, 2011, pp.45-66. |
| Abstract | The 24 April 2002 ML 5.2 Gnjilane earthquake was studied first through inversion of the Sg – Lg wave group displacement amplitude spectrum and P-nodal planes determination. The seismic moment, source spectrum corner frequency and Brune equivalent circular fault surface for this shock were obtained, respectively, as M0 = 6.48·1016 N·m, f0 = 0.59 Hz and Σs,eq = 15.2 km2. The P-nodal planes for the four strongest aftershocks and the distribution of other aftershocks’ epicentres were determined, too, and used in identifying the actual source mechanism of the main shock by a simple method that included also the vertical projections on the Earth’s surface of the main shock Σs,eq with the two main shock P-nodal planes as possible fault planes. It was found that the main shock was caused by a normal right lateral faulting in a plane which struck with an azimuth of 238° and dipped toward NNW under an angle of 22°. This faulting was associated with the shear stressed fault structure along the Pliocene-Quarternary sinking valley of Binačka Morava, and it led to activations of other ruptures as sources of a significant number of aftershocks. |
| Keywords | seismic cycle, rupturing, source mechanism, faulting, seismic moment, fault surface, corner frequency |
