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Alessandra Ascione

Bio: Alessandra Ascione is an academic researcher from University of Naples Federico II. The author has contributed to research in topics: Tectonics & Fault (geology). The author has an hindex of 18, co-authored 45 publications receiving 902 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, a large-scale topographic analysis, by processing 90m and 230m DEMs, is performed, with the reconstruction of magnitude and timing of surface uplift affecting a wide sector of the Central Apennines (Italy) by means of morphometric and morphostructural analyses.

106 citations

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TL;DR: Angelier et al. as mentioned in this paper combined structural and geomorphological investigations in two key areas, in order to obtain new data on the structure and evolution of the Tyrrhenian slope of the southern Apennines.

73 citations

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TL;DR: In this article, the authors focused on shallow-water to continental, Pliocene-Quaternary basins that formed on top of the Apennine allochthonous wedge after its emplacement onto a large foreland carbonate platform domain (Apulian Platform).
Abstract: In recent years, contrasting seismic tomographic images have given rise to an extensive debate about the occurrence and implications of migrating slab detachment beneath southern Italy. One of the most pertinent aspects of this process is the concentration of the slab pull force, and particularly its surface expression in terms of vertical motions and related basin subsidence/uplift. In this study we focused on shallow-water to continental, Pliocene-Quaternary basins that formed on top of the Apennine allochthonous wedge after its emplacement onto a large foreland carbonate platform domain (Apulian Platform). Due to the thick-skinned style of deformation controlling the Pliocene-Pleistocene stages of continental shortening, a high degree of coupling with the downgoing plate appears to characterize the late tectonic evolution of the southern Apennines. Therefore, the wedgetop basins analysed in this study, although occurring on the deformed edge of the overriding plate, are capable of recording deep geodynamic processes affecting the slab. Detailed stratigraphic work on these wedge-top basins points to a progressive SE-ward migration of basin subsidence from c. 4 to c. 2.8 Ma over a distance of about 140 km along the strike of the Apennine belt. Such a migration is consistent with a redistribution of slab-pull forces associated with the progressive lateral migration at a mean rate in the range of 12–14 cm y–1 of a slab tear within the down-going Adriatic lithosphere. These results yield fundamental information on the rates of first-order geodynamic processes affecting the slab, and on related surface response.

72 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the epicentral area of the M S = 6.9, 1980 Irpinia earthquake based on detailed topography analyses, morphostratigraphic and structural data, and new age constraints from Quaternary deposits.
Abstract: A significant uncertainty exists in the definition of both surface pattern and subsurface continuity (i.e., coupling vs. decoupling) of active normal faults in the Apennines. In this study, we investigated the epicentral area of the M S = 6.9, 1980 Irpinia earthquake—one of the most destructive historical earthquakes in Italy—based on detailed topography analyses, morphostratigraphic and structural data, and new age constraints from Quaternary deposits. The active tectonic behavior of the study area is controlled by a series of subparallel, mainly WNW-ESE– to NW-SE–trending, dominantly extensional faults spanning over the southern Apennines axial belt. A large part of the active fault strands is characterized by a subdued topographic expression, as a result of the young age of extensional faulting initiation, and of relatively low mean slip rates. In addition, as already known from long historical seismicity records elsewhere, long-lasting quiescence might alternate with clusters of closely spaced, strong earthquakes. The long-term morphostratigraphic record confirms that long-lasting quiescence may punctuate fault activity, with major implications for seismic hazard assessment. The relatively small-sized cumulative fault throws estimated by surface evidence contrast with subsurface information provided by crustal-scale cross sections and seismological evidence, which both suggest the occurrence at depth of large-displacement, mature fault zones capable of nucleating large earthquakes. Furthermore, although the surface distribution of active fault strands overlaps the belt affected by present-day low-magnitude seismicity and by large historical earthquakes, a mismatch in the attitude and kinematics of shallow versus deep faults is unraveled by a comparison of surface geological versus seismological data sets. This feature suggests a decoupling between surface and deep fault zones, and that outcropping fault planes cannot always be straightforwardly traced down to hypocentral depths, particularly in fold-and-thrust belts characterized by strong rheological contrasts. On the other hand, stress inversion from outcropping active faults and from earthquake focal mechanisms indicates a general consistency of the stress field, thus suggesting that a homogeneous late Quaternary extensional regime produces complex reactivation of the inherited, articulated fault network affecting different structural levels of the southern Apennines.

71 citations

Journal ArticleDOI
TL;DR: In this paper, low-temperature thermochronometry data indicate that exhumation of previous tectonically buried sedimentary units started at around 10.5 million years ago and took place mostly during the last 6 million years.
Abstract: In the southern Apennines, low-temperature thermochronometry data indicate that exhumation of previous tectonically buried sedimentary units started at around 10 Ma and took place mostly during the last 6 Ma. Relatively high exhumation rates are obtained from apatite fission track (AFT) and (U-Th)/He (AHe) analysis, pointing to a substantial contribution of tectonic processes to rock exhumation besides erosion. Exhumation rates derived from new apatite (U-Th)/He data (AHe) for the last 3 Ma are generally lower than rates determined by AFT data and almost in line with erosion rates inferred from cosmogenic nuclides and sediment yield, thus suggesting that tectonic exhumation was dominant during the older exhumation stages of this region. However, younger cooling ages in the Monte Alpi area from both AFT and AHe analyses point out focused exhumation during the last 3 Ma. Structural and morphotectonic analyses indicate that fast exhumation occurred specifically in this area—where the Apulian Platform reservoir carbonates, elsewhere buried beneath a several kilometer-thick allochthonous cover, are exposed at the surface—as a result of a complex interplay between steep-rooted reverse faulting and shallow low-angle extension. This deformation involved the development of foreland-dipping low-angle normal faults affecting the allochthonous cover units during the late stages of reverse fault-related anticlinal growth in the underlying buried carbonates. Extension of the region triggered focused exhumation in the footwall of the extensional low-angle faults, which was followed by widespread crustal extension and associated development of high-angle normal faults, leading to surface uplift of Monte Alpi.

51 citations


Cited by
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01 Jan 2015
TL;DR: The work of the IPCC Working Group III 5th Assessment report as mentioned in this paper is a comprehensive, objective and policy neutral assessment of the current scientific knowledge on mitigating climate change, which has been extensively reviewed by experts and governments to ensure quality and comprehensiveness.
Abstract: The talk with present the key results of the IPCC Working Group III 5th assessment report. Concluding four years of intense scientific collaboration by hundreds of authors from around the world, the report responds to the request of the world's governments for a comprehensive, objective and policy neutral assessment of the current scientific knowledge on mitigating climate change. The report has been extensively reviewed by experts and governments to ensure quality and comprehensiveness.

3,224 citations

Journal ArticleDOI
TL;DR: In this paper, the main natural and human-induced hazards characteristic of karst environments, with specific focus on sinkholes, floods and slope movements, are reviewed, and summarized the main outcomes reached by experts regarding the assessment of environmental impacts and their mitigation.

565 citations

Proceedings Article
01 May 2008
TL;DR: In this paper, the authors provide an overview of the basic concepts of radar interferometry and an introduction to some of its applications, including topographic map generation, surface deformation mapping, landslide monitoring, vegetation structure determination and change detection.
Abstract: Since its inception 30 years ago perhaps no innovation in radar technology has made such a tremendous impact on the field as that of radar interferometry. Radar interferometry uses two or more observations separated in either time or space to measure fraction of a wavelength scale range differences between the two observations. Radar interferometry is used by scientific, commercial and government institutions for numerous applications including topographic map generation, surface deformation mapping, landslide monitoring, current velocity measurement, vegetation structure determination and change detection. Radar interferometers can be flown on either spaceborne or airborne platforms or be fixed observing systems. This course is designed to provide an overview of the basic concepts of radar interferometry and an introduction to some of its applications. The course will cover basic radar imaging principles, a geometric and imaging signal perspective of the interferometric phase, interferometric correlation, basic sensitivity equations, phase unwrapping, topographic mapping and repeat pass interferometry for deformation measurements. The principles will be illustrated with examples from both spaceborne and airborne interferometric data sets. An overview of some of the major applications of radar interferometry will be presented with an emphasis on topographic and deformation mapping. The course will also briefly touch upon permanent scatter methods and polarimetric interferometry.

349 citations

Journal ArticleDOI
TL;DR: In this paper, the authors obtained a kinematic estimations of the southern Apennines/Calabria-Peloritani terrane system evolution from the Late Oligocene to Recent.

120 citations

Journal ArticleDOI
TL;DR: In this paper, the authors used persistent scatterer interferometry (PSI) from radar satellites ERS (European Remote Sensing satellite) and ENVISAT (Environmental Satellite) for updating a pre-existing landslide inventory (LSI) map: the main purpose is to change or confirm the landslide state of activity and geometry and to identify new landslides.
Abstract: This work illustrates the contribution of persistent scatterer interferometry (PSI) from radar satellites ERS (European Remote Sensing satellite) and ENVISAT (Environmental Satellite) for the updating of a pre-existing landslide inventory (LSI) map: the main purpose is to change or confirm the landslide state of activity and geometry and to identify new landslides. Radar data have been integrated with optical images and ancillary data in a 1320 km2 wide river basin (Biferno Basin) located in the central-eastern part of Italy. The geological setting of the area is characterized by clay and alternated clayey, silt and sandy formations that are affected by slow landslides. Field validation confirmed the results and the capabilities of multi-interferometric synthetic aperture radar data, integrated and coupled with conventional techniques, to support landslide investigation at the regional scale thanks to the available archive of repeated satellite data, which provides measurements of ground displacements wit...

118 citations