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

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

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

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.JCR Journalope

The SHARE European Earthquake Catalogue (SHEEC) 1000–1899

In the frame of the European Commission project “Seismic Hazard Harmonization in Europe” (SHARE), aiming at harmonizing seismic hazard at a European scale, the compilation of a homogeneous, European parametric earthquake catalogue was planned. The goal was to be achieved by considering the most updated historical dataset and assessing homogenous magnitudes, with support from several institutions. This paper describes the SHARE European Earthquake Catalogue (SHEEC), which covers the time window 1000–1899. It strongly relies on the experience of the European Commission project “Network of Research Infrastructures for European Seismology” (NERIES), a module of which was dedicated to create the European “Archive of Historical Earthquake Data” (AHEAD) and to establish methodologies to homogenously derive earthquake parameters from macroseismic data. AHEAD has supplied the final earthquake list, obtained after sorting duplications out and eliminating many fake events; in addition, it supplied the most updated historical dataset. Macroseismic data points (MDPs) provided by AHEAD have been processed with updated, repeatable procedures, regionally calibrated against a set of recent, instrumental earthquakes, to obtain earthquake parameters. From the same data, a set of epicentral intensity-to-magnitude relations has been derived,with the aimof providing another set of homogeneous Mw estimates. Then, a strategy focussed on maximizing the homogeneity of the final epicentral location and Mw, has been adopted. Special care has been devoted also to supply location and Mw uncertainty. The paper focuses on the procedure adopted for the compilation of SHEEC and briefly comments on the achieved results

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

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.</jats:p

Laboratory and field testing assessment of next generation biocide-free, fouling-resistant slippery coatings

Recent research efforts to combat marine biofouling have focused on foul-release coatings that are not harmful for the marine environment. Inspired by nature, Slippery lubricant infused porous surfaces (SLIPS) is a surface modification technology platform with excellent antiadhesive and antifouling capacities. Precommercial coatings based on the SLIPS concept have demonstrated promising results as an environmentally friendly strategy to combat marine biofouling. Here, we investigated the resistance against marine biofouling of a range of recently developed, biocide-free SLIPS commercial coatings. The fouling resistance performance was evaluated both in the lab and in the field by conducting multimonth immersion tests in high-fouling pressure environments. In the lab, we show that the coatings are able to largely deter settlement of marine mussels - one of the most invasive marine biofouling organisms - and to weaken their interfacial adhesion strength. The key design parameter of slippery coatings to minimize fouling is the thickness of the entrapped lubricant overlayer, which can be assessed through depth-sensing nanoindentation measurements. We find that the surface energy (i.e., hydrophobic versus hydrophilic), on the other hand, does not significantly influence the antifouling performance of these coatings in lab-scale studies. After immersion in the field in stagnant waters, all coatings exhibited efficient foul-release capacity against macrofoulers, whereas under stronger hydrodynamic flow conditions, only weakly attached biofilms were detected with a bacterial community composition that is independent of the surface energy. These results suggest that these large-scale paintable coatings exhibit a strong marine biofouling resistance with low maintenance costs, which represents an important advantage from a commercial application perspective.Ministry of Education (MOE)National Research Foundation (NRF)Submitted/Accepted versionThis study was funded by the Singapore National Research Foundation under its Marine Science Research and Develop- ment Program (MSRDP), Grant MSRDP-P2