The single scattering model has been applied for the estimation of cod
a Q values for local earthquakes that occurred in northern Greece duri
ng the period 1983-1989 and recorded by the telemetered network of the
Geophysical Laboratory of the University of Thessaloniki. Coda Q esti
mations were made for four frequency bands centered at 1.5 Hz, 3.0 Hz,
6.0 Hz and 12.0 Hz and for the lapse time windows 10-20 sec, 15-30 se
c, 20-45 sec, 30-60 sec and 50-100 sec. The coda Q values obtained sho
w a clear frequency dependence of the form Q(c) = Q0f(n), while Q0 and
n depend on the lapse time window. Q0 was found equal to 33 and n equ
al to 1.01 for the time window of 10 to 20 sec, while for the other wi
ndows Q0 increased from 60 to 129, with n being stable, close to 0.75.
This lapse time dependence is interpreted as due to a depth dependent
attenuation. The high attenuation and the strong frequency dependence
found are characteristic of an area with high seismicity, in agreemen
t with studies in other seismic regions.