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Ascione, Alessandra
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Ascione, Alessandra
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- PublicationRestrictedDo moderate magnitude earthquake generate seismically induced ground effects? The case study of the Mw= 5.16, 29th December 2013 Matese earthquake (southern Apennines, Italy)Seismically induced ground effects characterize moderate to high magnitude seismic events, whereas they are not so common during seismic sequences of low to moderate magnitude. A low to moderate magnitude seismic sequence with a Mw = 5.16 ± 0.07 main event occurred from December 2013 to February 2014 in the Matese ridge area, in the southern Apennines mountain chain. In the epicentral area of the Mw = 5.16 main event, which happened on December 29th 2013 in the southeastern part of the Matese ridge, feld surveys combined with information from local people and reports allowed the recognition of several earthquake-induced ground effects. Such ground effects include landslides, hydrological variations in local springs, gas fux, and a fame that was observed around the main shock epicentre. A coseismic rupture was identifed in the SW fault scarp of a small-sized intermontane basin (Mt. Airola basin). To detect the nature of the coseismic rupture, detail scale geological and geomorphological investigations, combined with geoelectrical and soil gas prospections, were carried out. Such a multidisciplinary study, besides allowing reconstruction of the surface and subsurface architecture of the Mt. Airola basin, and suggesting the occurrence of an active fault at the SW boundary of such basin, points to the gravitational nature of the coseismic ground rupture. Based on typology and spatial distribution of the ground effects, an intensity I = VII−VIII is estimated for the Mw = 5.16 earthquake according to the ESI-07 scale, which affected an area of at least 90 km2.
254 4 - PublicationRestrictedMorphostructural setting of the Sangro and Volturno Rivers divide area (Central-Southern Apennines, Italy)(2007-01-15)
; ; ; ; ;Ascione, A.; Università degli Studi di Napoli "Federico II", Dipartimento di Scienze della terra, Largo S. Marcellino 10, 80138 Napoli ;Miccadei, E.; Università degli Studi di Chieti "Gabriele d'Annunzio", Diaprtimento di Scienze della Terra, via dei Vestini 31, 66013 Chiesti Scalo ;Villani, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Berti, C.; Università degli Studi di Chieti "Gabriele d'Annunzio", Diaprtimento di Scienze della Terra, via dei Vestini 31, 66013 Chiesti Scalo; ; ; Topography of the Apennines chain resulted from the combined action of tectonic displacements (related to thrusting and high-angle faulting), large-scale uplift and surface processes. In such mountainous settings, where strong erosion is often responsible for incomplete stratigraphic records of surface evolution of thrust belts, geomorphological analysis helps quantify these processes and provide a framework for interpreting the geologic history of these regions. We studied a 400 km2 area of the Central-Southern Apennines, covering Abruzzo, Lazio and Molise regions, by means of morphostructural analysis. This sector of the chain emerged during the Lower Pliocene and suffered a long-lasting erosion. Our study reveals a high relief landscape dominated by high-standing, resistant carbonates forming structure-controlled landforms (morphosculptures), and valleys underlain by erodible siliciclastics. Quaternary deposits are few and scattered, and they give poor constraints for the recognition of ancient base-levels. However, this study defines and identifies several upland erosional surfaces (paleosurfaces) that may be linked to ancient base-levels. On the basis of cross-cut relationships between paleosurfaces and structural landforms, we outlined a possible long-term geomorphological evolution of the study area. Most of the local tectonic displacements in this sector of the chain took place during Miocene and Pliocene, by means of thrusting and strike-slip faulting, whereas only localized extensional tectonics occurred during Quaternary times. Since the Pliocene, differential erosion promoted exhumation of carbonates and deep incision of pre-existing erosional surfaces. This strong erosion can be related to a regional base-level lowering promoted by large-scale uplift of the axial sector of the Central-Southern Apennines.298 64 - PublicationOpen AccessAssessing mantle versus crustal sources for non-volcanic degassing along fault zones in the actively extending southern Apennines mountain belt (Italy)The actively extending axial zone of the southern Apennine mountain belt of Italy is characterized by a substantial flow of nonvolcanic gas to the surface. In this study, we have analyzed the correlation between the active tectonic framework of the Matese Ridge area and the high gas emissions found to the southwest, which includes large amounts of CO2 (up to 99 vol%), CH4 (up to 0.55 vol%), and He (up to 52 ppmv). We measured CO2 and CH4 fluxes of up to 34000 g d–1 and 2000 g d–1, respectively, from zones of focused degassing (gas vents and associated strong diffuse emission). This anomalously high flux of CO2 (advective plus diffusive) indicates that the study area has one of the largest nonvolcanic natural emissions of CO2 ever measured on Earth. The isotope composition of C in CO2 and CH4 shows there is a dominant crustal contribution of emissions (as opposed to a source from the mantle), indicating that thermometamorphism of the buried Apulian Platform carbonates is probably the main cause of CO2 production. This process has likely been enhanced by Quaternary magmatism, which provides an additional local source of heat triggering decarbonation of Apulian Platform limestones and dolostones at depth. The advective flux is concentrated at gas vents located along active fault segments located at the western tip of a major crustal structure, the South Matese fault zone. We believe that the very high gas emission in the Matese Ridge area is the result of both the presence of a dense network of active fault strands, which provides efficient pathways for fluid flow toward the surface, and the dramatically reduced thickness of the clay-rich mélange zone acting elsewhere in the southern Apennines as a top seal overlying the buried Apulian Platform carbonates.
310 135 - PublicationOpen AccessPS-Insar data analysis: pre-seismic ground deformation in the 2009 L’Aquila earthquake region(2020)
; ; ; ; ; ; ; ; ; The accuracy of the millimetre-scale measurements made so far by the SAR systems, as well as the multi-temporal analysis methodologies, have provided impressive images of surface displacements in areas affected by strong earthquakes, and contributed to constrain the geometric and kinematic features of earthquake generating faults. The multi-temporal analysis of InSAR data is also being acknowledged as promising for the search of earthquake precursors. We have applied the multi-temporal PS-InSAR technique to the detection of pre- to post-seismic ground displacements in the region struck by the normal faulting 2009 L’Aquila earthquake. We have used ERS and ENVISAT PS-data sets from both ascending and descending orbits, covering a 20-year long time span. On the yearly-scale, we have identified a pre-seismic displacement pattern, which consists of opposite vertical motions that have affected the blocks in the hanging wall and footwall of the structure that is recognised as the surface trace of the earthquake-generating fault. In particular, we have highlighted a pre-seismic uplift for 4-5 years followed by subsidence (starting 6-8 months prior to the earthquake) of the hanging wall block, coeval to opposite vertical motions of the footwall block. We suggest that such a displacement pattern may represent an earthquake precursor signal.250 105 - PublicationOpen AccessActive Deformation and Relief Evolution in the Western Lurestan Region of the Zagros Mountain Belt: New Insights From Tectonic Geomorphology Analysis and Finite Element Modeling(2020-12)
; ; ; ; ; ; ; ; ; ; ; ; ; To unravel how and where coseismic and interseismic deformation impacts the spatial and temporal patterns of rock uplift of the Lurestan sector of the Zagros Mountains, we performed an investigation of the large‐scale features of topography and river network coupled with 2‐D finite element modeling. Geomorphological analysis and constraints from parameters such as elevation, local relief, normalized channel steepness index (ksn), river longitudinal profiles, and transformed river profiles (chi plots) were used to unravel the time‐space distribution of vertical motions. Whereas the much longer timescale over which topography grows and/or rivers respond to tectonic or climatic perturbations with respect to even multiple seismic cycles, the outputs of the finite element model yield fundamental information on the source of the late part of the spatiotemporal evolution of surface uplift recorded by the geomorphology. Model outputs shed new light into the processes controlling relief evolution in an actively growing mountain belt underlain by a major blind thrust. The outputs illustrate how coseismic slip controls localized uplift of a prominent topographic feature—the Mountain Front Flexure—located above the main upper crustal ramp of the principal basement thrust fault of the region, while continuous displacement along the deeper, aseismic portion of the same basement fault controls generalized uplift of the whole crustal block located farther to the NE, in the interior of the orogen.67 80 - PublicationOpen AccessThe Plio-Quaternary uplift of the Apennine Chain: new data from the analysis of topography and river valleys in Central Italy(2008-03-25)
; ; ; ; ; ;Ascione, A.; Università di Napoli Federico II ;Cinque, A.; Università di Napoli Federico II ;Miccadei, E.; Università di Chieti G. D'Annunzio ;Villani, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Berti, C.; Università di Chieti G. D'Annunzio; ; ; ; This study aimed at the reconstruction of magnitude and timing of uplift of a wide sector of the Central Apennines (Italy) by means of morphometric and morphostructural analyses. In the internal portion of the chain (where stratigraphic and geomorphological markers of past sea-level positions are lacking) the study was based on analysis of erosional landforms and river valleys. A large-scale topographic analysis was performed, processing 90-m and 230-m DEMs. The spatial distribution of several morphometric parameters, together with characteristic wavelengths of relief, allowed the distinction of three main regions affected by different cumulative surface uplift and tectonic/erosional fragmentation: a Peri-Tyrrhenian Belt; an Axial Belt; a Peri-Adriatic Belt. Particular attention was devoted to fluvial landforms, with analysis of longitudinal profiles and geometric pattern of the main stream-trunks and their relations with major structures. Major differences occur between the Tyrrhenian and Adriatic valley systems, the former being generally longitudinal and showing overall concave-upward longitudinal profiles, whereas the latter are generally transverse and possess less regular longitudinal profiles. Topographic features and river valleys architecture seem related to different styles and amounts of uplift in the three Belts. Within the study area, a narrower coast to coast transect (Gaeta-Vasto Transect, GVT) was investigated in detail, devoting particular attention to its axial sector, lying around the Apennines main divide (main divide area: MDA), and a possible scheme of the Quaternary surface uplift inside this transect was proposed. In the MDA, the main stages of landscape evolution and river network organization were reconstructed by analysis of paleosurfaces coupled with analysis of relic and present-day hydrographic network. This allowed recognition of a major phase of surface uplift (exceeding 1500 m in the Meta-Mainarde massif) occurred in response to thrusting during the Pliocene, whereas for the Quaternary uplift a minimum value around 400 m was estimated. Our study suggests that, during the Quaternary and in the GVT, the Peri-Tyrrhenian Belt suffered a subdued uplift operating over small wavelengths (10-15 km), while Axial and Peri- Adriatic Belts were subject to a stronger and long-wavelength (90 km) surface uplift, with maximum values (about 700 m) shifted NE of the Axial Belt and tapering to zero towards the Adriatic coast. The reconstructed pattern of uplift is coherent with the topographic properties of the three Belts and with the observed drainage features.175 1163 - PublicationRestrictedLate quaternary faulting within the Southern Apennines seismic belt: new data from Mt.Marzano area (Southern Italy)(2003)
; ; ; ; ;Ascione, S.; Dipartimento di Scienze della Terra, Università di Napoli ;Cinque, A.; Dipartimento di Scienze della Terra, Università di Napoli ;Improta, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Villani, F.; Dipartimento di Scienze della Terra, Università di Napoli; ; ; An integrated geomorphological and geophysical investigation was performed in order to reconstruct the Pliocene-Quaternary geomorphologic evolution and recent tectonics of Mt. Marzano massif (Southern Apennines, Italy). The study area belongs to a region of high seismic energy release, the last event being the strong (MS 6.9) 1980 Irpinia earthquake. Most of the main faults of the area ceased their activity before development of the Late Pliocene age palaeosurfaces, widely spread over the massif. Beginning in the lower part of the Middle Pleistocene, strong extensional tectonics took place in the southern portion of the massif. WNW-trending faults created the Buccino and S.Gregorio Magno depressions, which underwent subsidence until the Holocene, according to abundant morphostructural evidence. During the Late Quaternary, the N1501 trending Mt. Valva–Mt. Carpineta fault and the N110-1001 trending Mt. Ogna fault, previously sealed by Pliocene palaeosurfaces, also were re-activated. Morphostructural data were integrated with a high-resolution seismic survey across the Piano di Pecore basin, which is dammed by a fault that slipped 70 cm during the 1980 earthquake. This fault produced no more than 50–60m of throw during Quaternary times, most probably starting from 100 to 150 kyr BP.159 32 - PublicationOpen AccessLate Quaternary uplift and sea level fluctuations along the Tyrrhenian margin of Basilicata - northern Calabria (southern Italy): New constraints from raised paleoshorelinesNew analyses of marine terraces in the Tyrrhenian Sea margin of Basilicata - northern Calabria (southern Italy) have been carried out. In the study area, c. 25 km in length, an impressive flight of marine terraces occurs, with the highest terraces reaching ~160 m a.s.l. Detailed geomorphological-stratigraphical analyses on remnants of paleoshorelines located within 60 m a.s.l. have shown that the rocky coast of the investigated coastal stretch has been affected by multiple relative sea-level fluctuations, during which reworking of older shorelines has occurred. Dating of the coral Cladocora caespitosa and speleothems, either predating or postdating single paleoshorelines, has allowed the construction of a chronological framework for the identified relative sea-level markers, and their correlation with MIS 7, MIS 6e and distinct peaks of MIS 5. A mean uplift rate of c. 0.25 mm/y since the Last Interglacial has been quantified, one order of magnitude larger than previous estimates. The uplift rate value has been used to infer the elevations of MIS 5a, 5c and 6e sea level peaks, which are higher than those reported in most sea level curves worldwide, although consistent with several findings from the western Mediterranean. Our results demonstrate that a mere sequential correlation may be misleading in the interpretation of flights of marine terraces and indicates that multiple age controls are crucial to unravelling the complex interaction between uplift and sea-level fluctuations in uplifted coastal areas. The reconstructed MIS 5a, 5c and 6e sea level paleo-elevations, besides contributing to the assessment of late Quaternary sea-level fluctuations in the Mediterranean Sea, may contribute to constrain coeval ice sheets volume variations.
150 85 - PublicationRestrictedEvolution of the late Quaternary San Gregorio Magno tectono-karstic basin (southern Italy) inferred from geomorphological, tephrostratigraphical and palaecological analyses: tectonic implications(2006)
; ; ; ; ; ; ; ;Aiello, G.; Dip. Sc. della Terra, Università di Napoli ;Ascione, A.; Dip. Sc. della Terra, Università di Napoli ;Barra, D.; Dip. Sc. della Terra, Università di Napoli ;Munno, R.; Dip. Sc. della Terra, Università di Napoli ;Petrosino, P.; Dip. Sc. della Terra, Università di Napoli ;Russo Ermolli, E.; Dip. Sc. della Terra, Università di Napoli ;Villani, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;; ; ; ; ; The Pantano di San Gregorio Magno is a 4.7 km 2 large tectono-karstic basin located in the axial belt of the Southern Apennines, an area affected by intense seismicity. The basin was formed in the Middle Pleistocene and is presently undissected. It is filled by lacustrine sediments (clays, silts and pyroclastic sands) passing laterally into alluvial fan deposits. Geomorphological investigations were integrated with tephrostratigraphical, palynological and palaeoecological analyses of a 61 m thick core (not reaching the bedrock). The multiproxy analysis of the S. Gregorio Magno record shows that, over the last 200k yr, the basin hosted a freshwater lake with an oscillating level. Age constraints provided by the tephrostratigraphic record allowed estimation of the sedimentation rate, which varied strongly through time. Evolution of the basin resulted from the complex combination of tectonic subsidence, karst processes and changing amounts of sedimentary inputs. The latter was influenced by allogenic contributions related both to primary and reworked volcanoclastic inputs and was climate-driven. The overall evidence, which indicates that in the long-term the accumulation rate substantially counterbalanced the accommodation space created by faulting, suggests that the basin evolution was also modulated by changing subsidence rates.222 28 - PublicationOpen AccessFault motion reversals predating the Mw 6.3 2009 L'Aquila earthquake: insights from synthetic aperture radar data(2021)
; ; ; ; ; ; ; ; ; ; ; The millimetre accuracy of Synthetic Aperture Radar (SAR) measurements and related multi-temporal data analyses provide fundamental information on surface displacements caused by strong earthquakes. The multi-temporal analysis of SAR interferometry data allows for the geometry, kinematics and temporal behaviour of earthquake-generating faults to be better constrained, and is being acknowledged as a promising technique in the field of earthquake precursors. We used SAR data obtained by multi-temporal interferometric techniques such as Permanent Scatterers (PS) interferometry for the investigation of pre- to post-seismic ground displacements in the region struck by theMw 6.3, 2009 L’Aquila earthquake.We analysed Europen Remote Sensing (ERS) and Envisat PS-datasets from ascending and descending orbits, and COSMO-SkyMed PS-datasets from descending orbit, collectively covering a > 20 year long time span. On a yearly scale, a reversal of motions that affected the hanging-wall and footwall blocks of the earthquake-generating fault is detected. In particular, the hanging-wall block is characterized by pre-seismic uplift – which we document as being independent of any hydrological control – and eastward horizontal motion for about six years, followed by subsidence and westward motion (starting six to eight months prior to the earthquake). We suggest that such a ground displacement pattern may represent an earthquake precursor signal.121 27