Seismic Source Parameters for the M<Subscript>L</Subscript>=5.4 Athens Earthquake (7 September 1999) from a New Telemetric Broad Band Seismological Network in Greece

A regional telemetric network of twelve digital broad-band seismic stations has been in full operation since the beginning of 1999, in Greece, operated by the Institute of Geodynamics of the National Observatory of Athens (GI-NOA). On 7 September1999, a M<Subscript>L</Subscript>=5.4 main shock occurred just 18 kilometers to the north of the Greek capital Athens, causing severe damage and loss of life. The broad band network recorded the seismic sequence and the main shock and 18 aftershocks were selected in order to determine their seismic source parameters and scaling relations by the spectral analysis method. The results indicate a main shock seismic momentM<Subscript>0</Subscript>=5.7 × 10<Superscript>24</Superscript> dyn-cm in general agreementwith that reported by other agencies and two different source models were used to determine the respective fault radii and displacements for comparison and evaluation purposes. In addition, by investigating source parameters for the aftershocks, it was found that the seismic moment correlates very well with the earthquake magnitude (M<Subscript>L</Subscript>) and corner frequency (F<Subscript>C</Subscript>) through the following relationships:Log M<Subscript>0</Subscript>=1.80M<Subscript>L</Subscript> + 15.19 and Log M<Subscript>0</Subscript>=- 3.17F<Subscript>C</Subscript> + 22.09,respectively. These results and scaling relations are in general agreement with those obtained by other studies and in view of the fact that digital seismic instrumentation is now expanding in Greece, these first results from spectral analysis of digital broad band data can be considered useful for future relevant investigations. Copyright Kluwer Academic Publishers 2002