In Situ and Laboratory Tests for the Evaluation of Dynamic Geotechnical Properties of a Cohesive Deposit in Florence

In order to determine dynamic parameters to use for seismic microzoning purposes in a new development area near Florence, the dynamic behavior of the alluvial silty clays situated in the upper 60 m of the deposit was experimentally investigated using geophysical surveys and cyclic laboratory tests. Previous studies on the geotechnical properties of the clays of Florence revealed that, in spite of some similarities in a comparison with other coeval clays described in the literature this soil exhibits a few anomalies, as e.g. higher variations between field and laboratory shear waves velocities and remarkable differences in the coefficients of the empirical relations that link the shear modulus to other geotechnical parameters. Moreover, many current correlations from CPT and DMT tests resulted not valid. This peculiar behavior cannot be explained in terms of cementation, because the carbonatic contents values, even if scattered, are practically normal. The objectives of the test program herein described were, therefore, as much to deepen our knowledge of the dynamic behavior of the soil both in situ and in laboratory, at low and high strain level, as to find out the reasons for this different behavior, by examining the possible influence of sample disturbance and of long-term effects, as well as of different geophysical survey techniques. The results of crosshole tests (CH), of spectral analysis of superficial waves surveys (SASW), of resonant column tests (RC) and of triaxial tests with measurement of shear and longitudinal wave velocities (Vt1), as well as the empirical relationships obtained between geotechnical parameters are analyzed and discussed

Arc-continent collisions, sediment recycling and the maintenance of the continental crust

Author Posting. © Geological Society of London, 2009. This is the author's version of the work. It is posted here by permission of Geological Society of London for personal use, not for redistribution. The definitive version was published in Geological Society, London, Special Publications 318 (2009): 75-103, doi:10.1144/SP318.3.Subduction zones are both the source of most new continental crust and the locations where crustal material is returned to the upper mantle. Globally the total amount of continental crust and sediment subducted below forearcs currently lies close to 3.0 Armstrong Units (1 AU = 1 km3/yr), of which 1.65 AU comprises subducted sediments and 1.33 AU tectonically eroded forearc crust. This compares with average ~0.4 AU lost during subduction of passive margins during Cenozoic continental collision. Individual margins may retreat in a wholesale, steady-state mode, or in a slower way involving the trenchward erosion of the forearc coupled with landward underplating, such as seen in the central and northern Andean margins. Tephra records of magmatism evolution from Central America indicate pulses of recycling through the roots of the arc. While this arc is in a state of long- term mass loss this is achieved in a discontinuous fashion via periods of slow tectonic erosion and even sediment accretion interrupted by catastrophic erosion events, likely caused by seamount subduction. Crustal losses into subduction zones must be balanced by arc magmatism and we estimate global average melt production rates to be 96 and 64 km3/m.y./km in oceanic and continental arc respectively. Key to maintaining the volume of the continental crust is the accretion of oceanic arcs to continental passive margins. Mass balancing across the Taiwan collision zones suggests that almost 90% of the colliding Luzon Arc crust is accreted to the margin of Asia in that region. Rates of exhumation and sediment recycling indicate the complete accretion process spans only 6–8 m.y. Subduction of sediment in both erosive and inefficient accretionary margins provides a mechanism for returning continental crust to the upper mantle. Sea level governs rates of continental erosion and thus sediment delivery to trenches, which in turn controls crustal thicknesses over 107– 109 yrs. Tectonically thickened crust is reduced to normal values (35–38 km) over timescales of 100–200 Ma.PC wishes to thank the Alexander von Humboldt Foundation for support during the writing of this paper at the University of Bremen, as well as the College of Physical Sciences, University of Aberdeen for its generous support

Self help groups in a city of Tuscany: Reconstruction of the second generation model of work for professionals and services

This study is part of a more extensive project aimed to investigate the effectiveness of self-help group participation in improving quality of life in mental disease. The study is taking place in the Tuscany Region, in Italy. In the first qualitative step of analysis researchers are interested in describing the specific features of the psychiatric self-help movement in Tuscany, comparing different realities, networks, kind of groups. Therefore, our aim is to collect exhaustive information to describe how self-help system work in different provinces at the present moment. The implementation of groups for psychiatric problems is quite young in Italy.  Because of a lack of specific regulation in the directives of the Italian health care system, every local service has implemented groups differently, sometimes enhancing, sometimes dismissing them. Prato, near Florence, is one of the more interesting context for the birth of psychiatric self-help movement in the region: public health services improved groups since early 90’s, it was one of the first self-help reality linked to services in the entire region. Now we are in a “second generation” of professionals, and the original meaning of groups seems to be transformed, sometimes misunderstood. Our objectives of study head us toward an in depth analysis of self-help phenomenon in Prato

Self help groups in a city of Tuscany: Reconstruction of the second generation model of work for professionals and services

This study is part of a more extensive project aimed to investigate the effectiveness of self-help group participation in improving quality of life in mental disease. The study is taking place in the Tuscany Region, in Italy. In the first qualitative step of analysis researchers are interested in describing the specific features of the psychiatric self-help movement in Tuscany, comparing different realities, networks, kind of groups. Therefore, our aim is to collect exhaustive information to describe how self-help system work in different provinces at the present moment. The implementation of groups for psychiatric problems is quite young in Italy.  Because of a lack of specific regulation in the directives of the Italian health care system, every local service has implemented groups differently, sometimes enhancing, sometimes dismissing them. Prato, near Florence, is one of the more interesting context for the birth of psychiatric self-help movement in the region: public health services improved groups since early 90’s, it was one of the first self-help reality linked to services in the entire region. Now we are in a “second generation” of professionals, and the original meaning of groups seems to be transformed, sometimes misunderstood. Our objectives of study head us toward an in depth analysis of self-help phenomenon in Prato

Modelling tectonic deformation along the North-Anatolian Fault in the Sea of Marmara

Using analogue techniques, we attempted to model the complex tectonic deformation pattern observed along the North-Anatolian Fault in the Sea of Marmara from morpho-bathymetry and seismic reflection images. In particular this paper focuses on the so-called Cinarcik segment of the fault connecting the eastern Izmit segment, which entirely ruptured during the Mw 7.4, 1999 earthquake, to the western segment of the Central High. The Çınarcık segment, potentially loaded after the Izmit earthquake, is expected to rupture during an earthquake occurring in the near future, possibly the next decades, with a high potential to affect the Istanbul metropolitan area. Our analysis suggests that the development of the observed structures accommodating strike-slip, transtensional and transpressional deformations, could be explained by changes in the geometry of fault segments within a right-lateral strike-slip tectonic regime. Tectonic deformations were reproduced in the analogue model by imposing a small (about 10°) and sharp difference in the relative orientations of the strike-slip segments at the edges of a major releasing bend. In the model slower strain accumulation occurs along the analogue of the Çınarcık segment than along the analogue of the Izmit segment of the fault. This would predict a delay for earthquakes triggered by stress transfer between the Izmit and Çınarcık segments. The model further predicts that most of the deformation in the Çınarcık basin is controlled by the sharp changes in the geometry of the fault itself