Search results for "level"
showing 10 items of 3465 documents
Vertical movements in NE Sicily and its offshore: Outcome of tectonic uplift during the last 125 ky
2013
New data in the coastal area between Acquedolci and Patti (northeastern Sicily, Italy) have been collected to calculate vertical tectonic rates in a key sector between the Kabilian-Calabrian and the Sicilian-Maghrebian chain. The comparison among marine geology data (multibeam and seismic reflection profiles) on the continental shelf-slope system and the radiocarbon ages on geomorphological markers collected during a coastal survey, provided new stratigraphic, geomorphological and biological data, contributing to the knowledge of the geological evolution of this sector for the last 125 ky.This coastal area is framed between two main structural features active during the Pleistocene in north…
Middle-Late Pleistocene marine terraces and fault activity in the Sant’Agata di Militello coastal area (north-eastern Sicily)
2012
Abstract The coastal sector of Sant’Agata di Militello (north-eastern Sicily) is characterized by a flight of raised Middle-Upper Pleistocene marine terraces occurring at different heights with respect to present sea level. In particular, the geomorphological survey and the analysis of stereo-pairs of aerial photographs allowed to recognize at least five main orders of well preserved Quaternary surfaces and relative deposits mostly located at the hanging wall and at the footwall of the Pleistocene northwest-dipping Capo d’Orlando normal fault, which controlled the geomorphological evolution of the coastal area. The marine terraces show an overall good morphological continuity and are formed…
Seismo-stratigraphic model of “La Bandita” area in the Palermo Plain (Sicily, Italy) through HVSR inversion constrained by stratigraphic data
2018
Ambient noise Horizontal-to-Vertical Spectral Ratio (HVSR) technique is commonly used approach to obtain 1D models of the shear-wave velocity in the shallow surface of an investigated area. However, obtained models can have a wide margin of uncertainty if inversions have not been appropriately constrained by detailed stratigraphic information. An application of HVSR inversion constrained by lithostratigraphic data is presented in order to verify the effectiveness of this technique for purposes of geological and geophysical reconstruction of a sedimentary basin in a densely urbanized area. This is often the case of seismic microzonation studies, in which almost all the information derives fr…
Elevation of the last interglacial highstand in Sicily (Italy): A benchmark of coastal tectonics
2006
Well-preserved MIS 5.5 terraces in Sicily are identified primarily by the index fossil Strombus bubonius, and dated by amino acid racemization (AAR), electron spin resonance (ESR), Uranium/Thorium (U/Th) and thermo luminescence (TL) methods. This review of published data and new results for the island of Sicily and neighbouring small islands of Egadi, Ustica and Lampedusa identifies areas of rapid uplift in the east (up to +175 m, elevation above sea level), slower uplift in the north (+29 m), and relative stability in the northwest (+2/+18 m). In contrast, about 250 km of the southern coastline of Sicily does not appear to contain MIS 5.5 outcrops. In eastern Sicily, correlation of MIS 5.5…
Lowstand carbonates, highstand sandstones?
2003
The sedimentary facies, sediment dynamics and sequence architecture of modern high-energy shelves in the mid and high latitudes are largely governed by wave abrasion processes. Cool-water carbonates may form there, if the influx and/or net accretion of siliciclastics is kept at a minimum. Little dilution of the carbonate produced in situ is generally promoted by a wide "epicontinental" shelf, subdued topography of the adjacent mainland, the predominance of limestone outcrops, and an arid climate. The aforementioned requirements are rarely met, and thus will automatically lead to the formation of mixed siliciclastic-cool-water carbonates. Such an example is found in the Early to Mid-Miocene …
Ice age at the Middle–Late Jurassic transition?
2003
A detailed record of sea surface temperatures in the Northern Hemisphere based on migration of marine invertebrate fauna (ammonites) and isotopic thermometry (δ18O values of shark tooth enamel) indicates a severe cooling at the Middle–Late Jurassic transition (MLJT), about 160 Ma ago. The magnitude of refrigeration (1–3°C for lower middle latitudes) and its coincidence in time with an abrupt global-scale fall of sea level documented through sequence stratigraphy are both suggestive of continental ice formation at this time. Ice sheets may have developed over the high-latitude mountainous regions of Far-East Russia. The drastic cooling just post-dated the Middle–Late Callovian widespread dep…
Trophic cascades in benthic marine ecosystems: lessons for fisheries and protected-area management
2000
An important principle of environmental science is that changes in single components of systems are likely to have consequences elsewhere in the same systems. In the sea, food web data are one of the few foundations for predicting such indirect effects, whether of fishery exploitation or following recovery in marine protected areas (MPAs). We review the available literature on one type of indirect interaction in benthic marine ecosystems, namely trophic cascades, which involve three or more trophic levels connected by predation. Because many indirect effects have been revealed through fishery exploitation, in some cases we include humans as trophic levels. Our purpose is to establish how wi…
Evolutionary Pathways of Political Representation in a Multi-Level Constitutional System: the Italian experience
2004
Il saggio cerca di studiare e individuare adeguati strumenti di raccordo e nuove forme di governance idonei ad assicuarare legittimità democratica ai sistemi politici complessi con particolare riferimento al sistema italiano profondamente mutato a seguito del processo di integrazione europea e dopo la riforma del titolo V della Costituzione italiana.
Cross-Frequency Coupling in Developmental Perspective
2019
It is generally assumed that different electroencephalogram (EEG) frequency bands are somehow related to different computational modes in the brain. Integration of these computational modes is reflected in the phenomenon of cross-frequency coupling (CFC). On slow temporal scales, CFC may reflect trait-like properties, which posits a question of its developmental trends. This is the first study that explored source-level CFC measures in a developmental perspective using both cross-sectional and longitudinal designs. CFC measures demonstrated good test-retest stability and proved to be higher in adults in cortical areas participating in sensory-motor integration, response inhibition, and atte…