The 7 and 11 May 1984 earthquakes in Abruzzo-Latium (Central Italy): reappraisal of the existing macroseismic datasets according to the EMS98     

Laura Graziani  Andrea Tertulliani  Alessandra Maramai  Antonio Rossi  Luca Arcoraci 《Journal of Seismology》2017,21(5):1219-1227

The aim of this paper is to provide a complete and reliable macroseismic knowledge of the events that stroke a large area in Central Italy on 7 and 11 May 1984. Previous studies, together with original accounts integrated with new and unpublished information, have been gathered and examined in order to re-evaluate macroseismic intensities in terms of the European Macroseismic Scale (EMS98). New intensity maps have been compiled; the total number of localities with available information for both the shocks increases from 1254 of the previous study to 1576. On the basis of the new dataset, the macroseismic magnitude of the first shock is M_W 5.6 which is lower than the previous macroseismic computation (M_W 5.7). Moreover, the topic of assessing macroseismic intensity in the presence of multiple shocks has been also investigated, proposing an unconventional approach to presenting the macroseismic data: an overall picture of the cumulative effects produced by all the seismic sequence is given to support a partial but faithful reconstruction of the second shock. This approach is inspired by the common experience in interpreting historical seismic sequences and gives a picture of the impact of the 1984 events on the territory.  相似文献   

New Caledonia Ophiolite, Marginal Rifting to Fore-arc Evolution     

Dominique CLUZEL  Jonathan AITCHISON  Arianna SECCHIARI  Alessandra MONTANINI  Delphine BOSCH 《《地质学报》英文版》2020,94(Z1):9-10

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Combining IR and X‐ray microtomography data sets: Application to Itokawa particles and to Paris meteorite     

Zelia Dionnet  Rosario Brunetto  Alice Alon‐Toppani  Stefano Rubino  Donia Baklouti  Ferenc Borondics  Anne‐Ccile Buellet  Zahia Djouadi  Andrew King  Tomoki Nakamura  Alessandra Rotundi  Christophe Sandt  David Troadec  Akira Tsuchiyama 《Meteoritics & planetary science》2020,55(7):1645-1664

In the near future, a new generation of sample return missions (Hayabusa2, OSIRIS‐REx, MMX, etc.) will collect samples from small solar system bodies. To maximize the scientific outcome of laboratory studies and minimize the loss of precious extraterrestrial samples, an analytical sequence from less destructive to more destructive techniques needs to be established. In this work, we present a combined X‐ray and IR microtomography applied to five Itokawa particles and one fragment of the primitive carbonaceous chondrite Paris. We show that this analytical approach is able to provide a 3‐D physical and chemical characterization of individual extraterrestrial particles, using the measurement of their 3‐D structure and porosity, and the detection of mineral and organic phases, and their spatial co‐localization in 3‐D. We propose these techniques as an efficient first step in a multitechnique analytical sequence on microscopic samples collected by space missions.  相似文献   

Common signals between physical and atmospheric variables and zooplankton biomass in the Subarctic Pacific     

Conversi  Alessandra; Hameed  Sultan 《ICES Journal of Marine Science》1998,55(4):739-747

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The macrozoobenthos of the Karavasta lagoon system (Albania): local assemblages and geographical comparisons     

Carlotta Nonnis Marzano  Maria Flavia Gravina  Alessandra Fianchini  Giuseppe Portacci  Myriam Gherardi  Angelo Tursi  Giuseppe Corriero 《Marine Ecology》2010,31(4):622-632

The macrozoobenthic assemblage from the Karavasta lagoon system, the main wetland of Albania, was studied on soft bottoms and artificial hard substrates. Three different communities were identified: the typical ‘brackish‐water community’, an ‘outlet community’ dominated by filter‐feeders, and a typical ‘marine community’, inhabiting fine sandy bottoms, where polychaetes are dominant, together with a few species of tunicates and bivalves, which colonize hard substrates. The occurrence of build‐ups of the bryozoan Conopeum seurati, settled on the upper portion of long submerged wooden poles, was the main feature of faunistic interest. The faunistic affinity between the zoobenthic assemblage recorded in the hyperhaline lagoon of Karavasta and the assemblages from two Italian lagoons, the brackish Lake of Lesina and the euhaline Lake of Fogliano, was considered according to the different hydrological conditions and the geographical location. Hydrological confinement and salinity were likely to be the leading factors influencing the benthic community composition in the Karavasta wetland area. Therefore, on a vaster spatial scale, the isolation and geographical proximity of the ecosystems and colonizing ability and dispersal changes of the species appear to be the main factors liable to produce faunal variations.  相似文献   

Three-dimensional nonlinear random wave groups in intermediate water depth     

Felice Arena  Alfredo Ascanelli  Vincenzo Nava  Diego Pavone  Alessandra Romolo 《Coastal Engineering》2008,55(12):1052-1061

High waves at ocean occur during a complex space–time evolution of wave groups. In this paper the nonlinear structure of three-dimensional sea wave groups at intermediate water depth is investigated. To this purpose, the Boccotti's Quasi-Determinism theory is firstly applied to describe the linear wave groups when a given exceptionally high crest occurs. Then, the second-order correction to the linear solution is derived for the general condition of three-dimensional wave groups, at a finite water depth. Several numerical applications, finally, have been carried out in order to show how both the spectral bandwidth and the directional spreading modify the nonlinear high waves at different water depth.  相似文献   

Macroseismic evidence and site effects for the Lunigiana (Italy) 1995 Earthquake     

Andrea Tertulliani  Alessandra Maramai 《Journal of Seismology》1998,2(3):209-222

On October 10, 1995, an M_L= 4.8 (ING) earthquake occurred in the region of Lunigiana (northwestern Italy). The shock was felt over a large area and produced significant damage. We performed a macroseismic survey and damage zonation and assessed a maximum intensity VII MCS in the epicentral area. The damage pattern, that we investigated in detail for some of the villages in the most heavily damaged area, emphasises the role of surface geology in amplifying the effects. Topographic effects and near-surface geology are largely responsible for broadening the damage area. Given the moderate size of the earthquake, many of the macroseismic observations, including rotations of objects and the propagation of visible waves in the ground, are suggestive of amplification phenomena.  相似文献   

Second Italian meeting on celestial mechanics     

Alessandra CellettiAndrea MilaniEttore Perozzi 《Planetary and Space Science》1998,46(11-12)

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Multicriteria analysis applied to landslide susceptibility mapping     

Juliana F. Lorentz  Maria Lucia Calijuri  Eduardo Gomes Marques  Alessandra Carreiro Baptista 《Natural Hazards》2016,81(1):41-54

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Petrogenesis of basalts and gabbros from an ancient continent–ocean transition (External Liguride ophiolites, Northern Italy)     

Alessandra Montanini  Riccardo Tribuzio  Luigi Vernia 《Lithos》2008,101(3-4):453-479

Remnants of a fossil continent–ocean transition similar to that of the modern non-volcanic continental margins are preserved in the Jurassic External Liguride units. They consist of fertile lherzolites of subcontinental origin, MOR-type basalts and rare gabbroic intrusives, together with continental crust bodies exhumed during the rifting phases preceding the oceanization. The gabbroic rocks include troctolites, (olivine) gabbros, Fe–Ti oxide-bearing gabbros and diorites. Trace element and Nd isotope compositions indicate that these rocks were derived from N-MORB melts variably evolved through fractional crystallisation. In the gabbroic rocks, high-temperature ( 900 °C) shearing along ductile shear zones is locally overprinted by amphibolite-facies recrystallization (T  650 °C), which was most likely assisted by seawater-derived fluids. Basalts crop out as lava flows and as dykes crosscutting mantle lherzolites and gabbroic rocks. They display nearly flat REE patterns and high Y/Nb values (5–14), similar to modern N-MORB. Basalts are also characterised by weak Zr enrichment relative to neighbouring REE (Zr/Zr = 1.1–1.7) and high (Sm/Yb)_DM ratios (1.5–1.8). Their Nd isotope compositions are close to typical depleted mantle (initial _Nd = +7.6 to + 9.4). The geochemical features of parental melts of basaltic and gabbroic rocks may be attributed to melting of a MORB-type asthenospheric source. Trace element modelling shows that low-degree (≤ 6%) fractional melting of a depleted spinel peridotite cannot account for the elevated Sm/Yb ratios of basalts. Low-degree melting of a mixed source of spinel peridotite with small amounts of garnet pyroxenite has been proposed to explain the trace element signature of basalts.  相似文献