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Ettore Valente

Other affiliations: University of Molise
Bio: Ettore Valente 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 12, co-authored 29 publications receiving 330 citations. Previous affiliations of Ettore Valente include University of Molise.

Papers
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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

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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

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TL;DR: In this article, stream length-gradient, normalized channel steepness, stream convexity and first-order channel gradient indices from 10m digital elevation data from the southern Apennines region exhibit stream profile inconsistencies along the current drainage divide and a dominance of high values subparallel but inboard of the primary chain axis.

31 citations

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TL;DR: The Campi Flegrei, one of the largest volcanic fields in the world as mentioned in this paper, is a very young landscape, originated from 40 ka in response to strong and explosive volcanic processes.
Abstract: Naples and its surroundings are a very young landscape, originated from 40 ka in response to strong and explosive volcanic processes, which created the Campi Flegrei, one of the largest volcanic fi...

30 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented a tectonic-geomorphological map (scale 1:40,000) of the Abruzzo Apennines, which is the result of a morphotectonic investigation of the middle Aterno River valley, which includes the area from the western L'Aquila-Coppito basin to the Paganica-San Demetrio basin and to the Castelnuovo-Civitaretenga basin.
Abstract: After the 6 April, 2009 normal faulting L'Aquila earthquake (Mw 6.3), the attention of many scientists was drawn to the Abruzzo Apennines. Until that time few studies had addressed the geomorphological and morphotectonic features of this area and none to extensive geomorphological mapping.The tectonic-geomorphological map (scale 1:40,000) presented in this work is the result of a morphotectonic investigation of the middle Aterno River valley, which includes the area from the western L'Aquila-Coppito basin (to the northwest) to the Paganica–San Demetrio basin and to the Castelnuovo–Civitaretenga basin (to the southeast).The map is implemented within a GIS environment by means of: DEM and map-based cartographic analysis and morphometry of orography and hydrography (raster and vector data scale 1:25,000, 10 m grid DEM), photogeological analysis (scale 1:10,000), structural geomorphological field mapping (scale 1:10,000), basin fill geometry analysis (geophysical and borehole investigations) and tectonic–geom...

30 citations


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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

01 Apr 2017
TL;DR: This is the first reconstruction of pre-eruptive magma transfer at Campi Flegrei and corroborates the existence of a stationary oblate source, below the caldera centre, that has been feeding lateral eruptions for the last ~5 ka.
Abstract: Calderas are collapse structures related to the emptying of magmatic reservoirs, often associated with large eruptions from long-lived magmatic systems. Understanding how magma is transferred from a magma reservoir to the surface before eruptions is a major challenge. Here we exploit the historical, archaeological and geological record of Campi Flegrei caldera to estimate the surface deformation preceding the Monte Nuovo eruption and investigate the shallow magma transfer. Our data suggest a progressive magma accumulation from ~1251 to 1536 in a 4.6 ± 0.9 km deep source below the caldera centre, and its transfer, between 1536 and 1538, to a 3.8 ± 0.6 km deep magmatic source ~4 km NW of the caldera centre, below Monte Nuovo; this peripheral source fed the eruption through a shallower source, 0.4 ± 0.3 km deep. This is the first reconstruction of pre-eruptive magma transfer at Campi Flegrei and corroborates the existence of a stationary oblate source, below the caldera centre, that has been feeding lateral eruptions for the last ~5 ka. Our results suggest: 1) repeated emplacement of magma through intrusions below the caldera centre; 2) occasional lateral transfer of magma feeding non-central eruptions within the caldera. Comparison with historical unrest at calderas worldwide suggests that this behavior is common.

97 citations

Journal ArticleDOI
TL;DR: In this article, the authors provide an analysis of the academic research on Geoparks, based on publications in the Scopus database in the period 2002-2020, using bibliometric analysis methods and bibliographic display maps.
Abstract: Since the Digne Convention in 1991, the literature related to Geoparks has gained a growing interest on the academy’s part, especially in achieving the preservation of geological interest sites through sustainable tourism. This article aims to provide an analysis of the academic research on Geoparks, based on publications in the Scopus database in the period 2002–2020. Bibliometric analysis methods and bibliographic display maps were examined using VOSviewer software. The bibliometric analysis process comprises three phases: (i) Search Criteria and Source Identification, (ii) software and data extraction, and (iii) data analysis and interpretation. The results show geoparks in full growth as a scientific discipline, thanks to the contribution of various authors, institutions, journals, and related topics that confirm the importance of this field of study. Additionally, bibliometric maps lead to an understanding of the intellectual structure of the subject, in which keyword co-occurrence analysis shows six main themes, ranging from ‘UNESCO Global Geoparks’ to ‘Geo-tourism-Sustainable Tourism’. this, combined with maps of co-citation, broadly exhibits this structure and development, showing areas of current interest and potential development, thus offering the latest knowledge on Geopark research worldwide. There is a growing concentration of research on geomorphological heritage and geo-tourism, focusing on methodologies to evaluate the specialities of this type of heritage and define the concept of geo-tourism; there is a great interest especially in the evaluation and identification of geo-site/geo-morphosites which try to eliminate subjectivity in methods and focus on sustainable development of the localities.

75 citations

Journal ArticleDOI
TL;DR: Aftershock patterns reveal that the Amatrice Mw5.4 aftershock and the Norcia mainshock ruptured two distinct antithetic faults 3–4 km apart, and suggest to consider both the MST cross structure and the subsidiary antithetic fault in the finite-fault source modelling of thenorcia earthquake.
Abstract: We present the first high-quality catalog of early aftershocks of the three mainshocks of the 2016 central Italy Amatrice-Visso-Norcia normal faulting sequence. We located 10,574 manually picked aftershocks with a robust probabilistic, non-linear method achieving a significant improvement in the solution accuracy and magnitude completeness with respect to previous studies. Aftershock distribution and relocated mainshocks give insight into the complex architecture of major causative and subsidiary faults, thus providing crucial constraints on multi-segment rupture models. We document reactivation and kinematic inversion of a WNW-dipping listric structure, referable to the inherited Mts Sibillini Thrust (MST) that controlled segmentation of the causative normal faults. Spatial partitioning of aftershocks evidences that the MST lateral ramp had a dual control on rupture propagation, behaving as a barrier for the Amatrice and Visso mainshocks, and later as an asperity for the Norcia mainshock. We hypothesize that the Visso mainshock re-activated also the deep part of an optimally oriented preexisting thrust. Aftershock patterns reveal that the Amatrice Mw5.4 aftershock and the Norcia mainshock ruptured two distinct antithetic faults 3–4 km apart. Therefore, our results suggest to consider both the MST cross structure and the subsidiary antithetic fault in the finite-fault source modelling of the Norcia earthquake.

73 citations

Journal ArticleDOI
TL;DR: In this paper, a trace and rare earth element characterization of single glass shards from fifteen tephra layers found in the astronomically-tuned KC01B deep-sea core (Ionian Sea, Central Mediterranean-36°15.25′N, 17°34.44′E, 3642m water depth) is presented.

73 citations