Italian seismic amplification factors for peak ground acceleration and peak ground velocity

Figures & data

Figure 1. Italian map of V_S30 (50° percentile) modified after Mori et al. (2020). Po plain and Apulia, discussed in the text, are shown in the figure.

Figure 2. Italian map of AF_PGA (50° percentile). Po plain and Apulia, discussed in the text, are shown in the figure.

An Italian map showing the distribution of the amplification factors for the 50° percentile in terms of peak ground acceleration, leading to recognize areas where lithostratigraphic site condition strongly modify the reference ground shaking as in the case of the north-west part of Italy or areas where no amplification of the reference ground shaking is expected as in the case of rocky sub-flat areas of the Apulian block.

Figure 3. Italian map of AF_PGV (50° percentile). Po plain and Apulia, discussed in the text, are shown in the figure.

An Italian map showing the distribution of the amplification factors for the 50° percentile in terms of peak ground velocity, leading to recognize areas where lithostratigraphic site condition strongly modify the reference ground shaking as in the case of the north-west part of Italy or areas where no amplification of the reference ground shaking is expected as in the case of rocky sub-flat areas of the Apulian block.

Figure 4. Box plots of the error ϵ_AF obtained comparing IGAG_20 AFs and results from site-specific LSSR analyses with reference to about 4,500 locations.

Box plots showing the distribution of the percentage error in computing the amplification factors by means of the IGAG_20 procedure with respect to the amplification factors based on local seismic site response analyses referring to about 4,500 Italian locations. The figure shows a mean value of the error distribution equal approximately to 9% and 2% with reference to peak ground acceleration and peak ground velocity, respectively.

Figure 5. An Italian map of AF_PGA (16° percentile).

Italian map showing the distribution of the amplification factors for the 16° percentile in terms of peak ground acceleration, leading to recognize areas where lithostratigraphic site condition strongly modify the reference ground shaking as in the case of the north-west part of Italy or areas where no amplification of the reference ground shaking is expected as in the case of rocky sub-flat areas of the Apulian block.

Figure 6. Italian map of AF_PGV (16° percentile).

Italian map showing the distribution of the amplification factors for the 16° percentile in term of peak ground velocity, leading to recognize areas where lithostratigraphic site condition strongly modify the reference ground shaking as in the case of the north-west part of Italy or areas where no amplification of the reference ground shaking is expected as in the case of rocky sub-flat areas of the Apulian block.

Figure 7. Italian map of AF_PGA (84° percentile).

An Italian map showing the distribution of the amplification factors for the 84° percentile in terms of peak ground acceleration, leading to recognize areas where lithostratigraphic site condition strongly modify the reference ground shaking as in the case of the north-west part of Italy or areas where no amplification of the reference ground shaking is expected as in the case of rocky sub-flat areas of the Apulian block.

Figure 8. Italian map of AF_PGV (84° percentile).

Italian map showing the distribution of the amplification factors for the 84° percentile in term of peak ground velocity, leading to recognize areas where lithostratigraphic site condition strongly modify the reference ground shaking as in the case of the north-west part of Italy or areas where no amplification of the reference ground shaking is expected as in the case of rocky sub-flat areas of the Apulian block.

Mori, F., Mendicelli, A., Moscatelli, M., Romagnoli, G., Peronace, E., & Naso, G. (2020). A new Vs30 map for Italy based on the seismic microzonation dataset. Engineering Geology, 275, Article 105745. https://doi.org/10.1016/j.enggeo.2020.105745

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Data availability statement

The data that support the findings of this study are available from Istituto di Geologia Ambientale e Geoingegneria (Institute of Environmental Geology and Geoengineering of the Italian National Council of Research). Restrictions apply to the availability of these data, which were used under license for this study. Data are available from the authors with the permission of Istituto di Geologia Ambientale e Geoingegneria (Institute of Environmental Geology and Geoengineering of the Italian National Council of Research).