  The frequency-dependent spectrum based seismic intensity, also called
instrumental intensity, is calculated basically from the integration of the
square values of spectral acceleration ordinates. The values of the
instrumental intensity are calibrated to match the values of the EMS-98
intensity scale, providing a promising analytical indicator for estimating the
destructive potential of earthquakes. Previous studies have shown that the
proposed index could be used as a basis for the development of a new improved
seismic intensity scale. The paper presents a set of maps describing the
spatial distribution of instrumental intensity ordinates for three seismic
events recorded in 1986 and 1990. These events, generated by the Vrancea
source, are the strongest earthquakes in Romania for which accelerographic data
was recorded at multiple stations. Intensity maps were generated for separate
significant frequency bands, in order to reveal the destructiveness of the
considered earthquakes for different building categories. Results were compared
and correlated with previous studies on Vrancea earthquakes and with
information provided by building damage reports from the considered
earthquakes.
