Seismic response of the geologic structure underlying the Roman Colosseum and a 2-D resonance of a sediment valley

P. Mozco, A. Rovelli, P. Labak, L. Malagnini

Abstract


The seismic response of the geologic structure beneath the Colosseum is investigated using a two-dimensional
modeling for a vertically incident plane SH wave. Computations indicate that the southern part of the Colosseum
may be exposed to a seismic ground motion with significantly larger amplitudes, differential motion and
longer duration than the northern part. because the southern part of the Colosseum is underlain by a sedimentfilled
valley created by sedimentary filling of the former tributary of the River Tiber. A 2-D resonance may
develop in the valley. Unlike the previous theoretical studies on 2-D resonance in sediment-filled valleys, an
effect of heterogeneous valley surroundings on the resonance is partly investigated. A very small sensitivity of
the maximum spectral amplifications connected with the fundamental and first higher modes to the presence of
a horizontal surface layer (with an intermediate velocity) in the valley surroundings is observed in the studied
models.

Keywords


Roman Colosseum;seismic waves;seismic response;site effect;2-D resonance;finite-difference method

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References


DOI: https://doi.org/10.4401/ag-4095

Published by INGV, Istituto Nazionale di Geofisica e Vulcanologia - ISSN: 2037-416X