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Riguzzi, Federica
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Preferred name
Riguzzi, Federica
Email
federica.riguzzi@ingv.it
Staff
staff
ORCID
Scopus Author ID
7003342502
Researcher ID
E-9694-2011
120 results
Now showing 1 - 10 of 120
- PublicationOpen AccessSannio-Matese Mounts (Southern Italy) deformation field from GPS Data (2002-2014)(Rend. Online Soc. Geol. It., Suppl. n. 1 al Vol. 31 (2014), 2014-09-09)
; ; ; ; ; ; ; ; ; ; ; ; ; ;Sepe, Vincenzo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Brandi, Giuseppe; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Cubellis, Elena; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;De Martino, Prospero; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Devoti, Roberto; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Dolce, Mario; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Esposito, Alessandra; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Galvani, Alessandro; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Massucci, Angelo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Obrizzo, Francesco; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Pietrantonio, Graziella; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Riguzzi, Federica; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Tammaro, Umberto; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ; ; ; ; ; ; ; ; A ML=4.9 earthquake occurred in the Sannio-Matese area at 18:08 on December 29 2013. The epicenter was located in the “Monti del Matese seismic district”. The epicentral area lies between the small towns of San Gregorio Matese, Cusano Mutri, Gioia Sannitica, Piedimonte Matese, San Potito Sannita in the Caserta province in an area with an high seismic Hazard. The area was struck by large and destructive earthquakes in the past (1456, 1688, 1702, 1732, 1805,1962) with maximum magnitude up to 7.2. Past and recent seismicity of the area is generally characterized by both single events and low energy seismic sequences (1885, 1903, 1905, 1990, 1992, 1997). The last sequence occurred on 1997 with the largest event (MD = 4.1, 19 March) occurred at the border between the Benevento and Campobasso provinces followed by an intense activity ended only in September of the same year. The epicentral distribution of the 1997 low energy (M ≤ 4.0) seismic sequence is mainly NE-SW oriented suggesting the activation of anti-Apennine faults. The December 29 2013 seismic event, is located very close to the 1688 earthquake area. Still open debate is the association of the main event of the sequence and its aftershocks with the seismogenic structures present in the area. The SAGNET (Southern Apennine Geodetic NETwork) is the Non-permanent GPS network covering the area between the Matese Mounts and the Mainarde–Meta Mountains and consists of 40 3D GPS vertices. GPS dataset consists of data recorded at non-permanent stations in the time spam 2002-2014 and at the Continuous GPS stations (CGPS) of the RING network (managed of INGV) located in the central and southern Apennines regions. We have calculated the GPS velocity field with permanent and non-permanent stations (with time series of at least 3 surveys). The horizontal velocity field, expressed with respect to a fixed Eurasian plate, shows a good coherence between the velocities field estimated from the SAGNET and CGPS. In this paper we have evaluated the strain rate in the Sannio-Matese area. Before the earthquake, GPS data analysis showed a decrease in the velocity in the southern sector of Matese Massif (where the December 29 2013 earthquake epicenter will be localized) with respect to the surrounding areas which is also evident from the lower values of the strain rate ranging between 15÷20 *10-9 yr-1. Lower GPS Strain rate has been recognized at the end of seismic cycle and appear as a useful tool to point out hazardous seismic areas as already highlighted in the 2009 L'Aquila and in the 2012 Emilia earthquakes.435 420 - PublicationOpen AccessThe INGV-CNT crustal motion map for the Euro-Mediterranean region(2015-04-12)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Serpelloni, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;D'Agostino, N.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Devoti, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Anzidei, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Avallone, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Cavaliere, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Cecere, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;D'Ambrosio, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Esposito, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Falco, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Galvani, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Pietrantonio, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Riguzzi, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Selvaggi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Sepe, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; ; ; ; ; ; ; ; ; ; ; ; ; ; Several thousands GPS/GNSS permanent stations, managed by both scientifc and cadastral institutions, are now available on the European plate and its boundaries. Data coming from these stations provide unprecedented spatial and temporal coverage of time-dependent deformation signals essential to understand the fundamental physics that govern tectonic deformation and faulting. The National Earthquake Center (Centro Nazionale Terremoti, CNT) of the National Institute of Geophysics and Volcanology (Istituto Nazionale di Geofisica e Vulcanologia, INGV) in Italy, is the Italian leader institution for the collection, management and scientific analysis of Global Positioning Systems (GPS) measurements. Distinct analysis centers independently and routinely process and analyze data using high-quality geodetic software (Bernese, Gamit, Gipsy) to measure the movements of >1000 points spanning the Eurasian plate and its boundaries. The goal of this project is to offer high-quality geodetic products, increase their accessibility to the European scientific community and promote the inter-disciplinary data exchange through a multi-level, user-friendly data gateway. These activities will be performed in strict contact with the GNSS Working Group of the EPOS project (http://www.eposeu.org) that is proposing to integrate, archive and distribute data, metadata and products for available GNSS stations on the European plate.384 561 - PublicationRestrictedKinematics and strain rates of the Eastern Himalayan Syntaxis from new GPS campaigns in Northeast IndiaNewly acquired GPS data along transects across Himalaya in Eastern Himalayan Syntaxis (EHS) reveal a clockwise rotation of rigid micro-plate comprising part of Brahmaputra valley, NE Himalaya and Northern Myanmar that rotates about a pole located at 14.5°N, 100.8°E at an angular rate of 1.75 ± 0.12°/Myr. The EHS is being torn-off from the main Indian Plate as a rigid block around which the kinematic clockwise rotation of Tibetan GPS sites toward the Sichuan-Yunnan region occurs in the Eurasia fixed frame. The residual velocity field of the newly acquired data estimated after removing the rotation that minimizes the GPS rates around EHS show a clear NE motion of the EHS sites, indentation of the rigid Indian plate into a less rigid area of the Eurasian plate. Themost extensive EHS zones of compression and shortening are in the direction of indenter convergence, with average values ranging between ~50–100 nanostrain/year. Along the frontal segment of EHS, from NWto SE, the shortening rate is reduced from the local maximum value of 160 to ~80 nanostrain/year, thus indicating a possibly locked fault patch of Mishmi or Lohit thrusts, the southernmost part of segment activated during the large 1950 Assam earthquake, Mw 8.6. An elastic block-model was invoked to infer the average slip rates of sections around EHS and to estimate an average locking depth of ~15 km. The slip rate perpendicular to the locked sector of EHS reaches 32.4mm/year and permits to roughly infer a recurrence time of ~200 year for an earthquake as energetic as the 1950 Assam event.
194 7 - PublicationOpen AccessIs global seismicity signed by the Markowitz wobble ?(2008-04)
; ;Riguzzi, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, ItaliaFor the past 108 years the worldwide occurrence of large seismic events shows a significant cyclic temporal pattern of about 34 years. The spectral analysis of the irregular Earth's polar motion over the last 108 years filtered from the secular drifts shows that both LOD and polhody are affected by the same significant periodicity. The third amplitude of polar motion at decadal periodicity in the terrestrial reference frame, after the Chandler and annual, is known as Markowitz wobble. The spectral coherence between the seismicity and polar motion is high at long periods, reaching saturation value at about 20 years. No significant delay is shown by the cross-correlation analysis between LOD, polhody and seismicity. If we accept the idea that global seismicity and polar motion are both signed by the Markowitz wobble, we can infer that they could be modulated by the same cause. Recent models hypothesize a gravitational and inertial coupling between the mantle and an inner core able to reproduce the Markowitz wobble on the polar motion. However, if the wobble signature on seismicity will be confirmed, this interpretation should probably be revised231 144 - PublicationRestrictedStatic vs Real-Time Coseismic Offset Comparison: The test case of 30 October, 2016 Central Italy earthquake(AUTh - School of Rural and Surveying Engineering, 2018)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; The knowledge of coseismic deformations due to earthquakes represents the fundamentals on which studies on seismic cycle and fault source mechanism are based on. Geodetic methods, in particular the recent developments of GNSS monitoring, are the only onescapable of providing the displacements of reference sites due to the occurrence of significant seismic events. Usually the detection of seismic offsets is done by comparing coordinates estimated before and after the earthquake. Here, considering the test case of the 30 October, 2016 central Italy seismic event, we show that it is possible to achieve such offsets also in real-time through the application of the new functionalities of the VADASE (Variometric Approach for Displacements Analysis Stand-alone Engine) approach. The comparison between the seismic offsets coming from the two approaches (static and realtime) is shown and discussed; the mean overall agreement is at the level of about half centimetre.94 10 - PublicationOpen AccessGravity and crustal dynamics in ItalyMapping the static gravity field in the Italian area is fundamental to identify the main lithospheric structures, to delineate the main geological elements at regional level and to infer the regional geodynamic setting. The ongoing tectonic processes highlight nevertheless the need to measure and model the time-variable gravity field, namely the dynamic gravity field, which requires increased accuracy and long time series of observations to separate the secular from the short-term variable components. The first, with a minor impact in Italy, are due to variations of ice mass balance (the viscoelastic response of the Earth to past changes in ice mass loading, and the elastic response of the Earth to present-day deglaciation), and the sealevel rise; the second are due to space/time variations of underground mass distributions, such as those related to seismic deformations, volcanic dynamics/eruptions and water transfer. Local-scale gravity studies along seismogenic faults may provide useful hints to study the seismic cycle and to unravel those areas more prone to seismic release by studying if the crustal volume is undergoing dilatancy (gravity decrease) or overpressure (gravity increase) before earthquake occurrence. This process, however, is accompanied by possible fluid migration, which can be revealed by other geophysical measurements, for example, by magnetotelluric and geoelectrical surveys. In this short paper, we briefly summarize the main sources of gravity variation providing on the same time orders of magnitude, spatial and temporal scales of their effects.
170 52 - PublicationRestrictedSatellite positioning and geophysics studies in Italy(2015-02-18)
; ; ; ; ;Baldi, P.; Dip. Fisica e Astronomia, Univ. di Bologna ;Devoti, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Riguzzi, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Pietrantonio, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; ; ; A brief historical overview of the Italian geophysical studies using satellite positioning observations.357 35 - PublicationUnknownThe velocity field of the Italian areaThe rapid development of several permanent GNSS networks in Italy has made available a huge amount of GNSS observations, giving the chance to figure out and significantly improve the spatial and temporal resolutions of the crustal deformation in the Italian area. More than 20 GNSS networks, promoted and managed by different institutions, constitute the grid of monitoring stations that includes over 1000 permanent stations, mainlydevoted to real-time positioning services but that has proven to be suitable for monitoring slow deforming processes, such as for instance, intraplate deformation processes. The whole set of raw GPS data is routinely processed at INGV providing daily solutions of station coordinates and estimating linear velocities for each station. The information content of coordinate time series is wide, the station position variations incorporate linear and non-linear effects caused by geophysical phenomena of different nature, of which we show some evidences. The sectors where the permanent network is augmented with non-permanent sites allows to study tectonic processes with a finer resolution.
303 4 - PublicationRestrictedRepeated GPS surveys across the Ionian Sea: evidence of crustal deformations(1996-05-13)
; ; ; ; ; ;Anzidei, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Baldi, P.; Dipartimento di Fisica - Università di Bologna - Italy ;Casula, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Crespi, M.; Dipartimento di Idraulica Trasporti e Strade - Università di Roma La Sapienza - Roma - Italy ;Riguzzi, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; ; ; ; Geodetic evidence of crustal deformation in the Ionian area detected by GPS surveys is given in this paper. a network consisting of nine geodetic sites crossing the Ionian sea from Calabria (southern Italy) to northwestern Greece was repeatedly surveyed, starting in 1991, within the framework of the TYRGEONET project. The results, obtained from processing data from three GPS campaigns performed on the same network in 1991, 1994 and recently in 1995, show significant changes in the positions of five sites. The deformations in terms of displacements (coordinate differences), are obtained by applying a rigorous statistical approach that analyses their significance by an original interactive procedure based on the classical F (Fisher) test. although more substantial geophysical conclusions require more observations, the estimated relative displacement pattern is generally coherent with the features of the main tectonic structures identified for this area. The detected deformations for the greek sites confirm the activity of the Kefalonia right-lateral transform fault, and a right-lateral motion of the Mattinata fault (northern Apulia) seems to have been detected by the Italian sites. Moreover, within the time span analysed, the site of Matera shows a different behaviour from the three Adriatic sites (Tremiti, M.S. Angelo and Specchia Cristi), since relative displacements among Matera and these sites were detected. This fact may indicate the weakness of the assumption, reported in some papers, that Matera could be a representative site of the motion of the whole Adriatic plate. Furthermore, the site of Specchia Cristi shows the maximum relative displacement in the network, with a vector magnitude of about 5 cm with a 3 cm confidence interval at the 95 percent level. therefore, even if some additional GPS observations are needed to achieve a clearer picture of the tectonic behaviour of the Ionian Sea area, the detected relative displacement pattern of the Italian sites agrees with a possible rotational behaviour of the Apulian platform with respect to the Adriatic plate, as already hypothesized by Finetti (1982).149 22 - PublicationOpen AccessA model of plate motion(2006)
; ; ; ; ; ;Riguzzi, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Crespi, M.; University La Sapienza, Rome, Italy ;Cuffaro, M.; University La Sapienza, Rome, Italy ;Doglioni, C.; University La Sapienza, Rome, Italy ;Giannone, F.; University La Sapienza, Rome, Italy; ; ; ; The wide use of space geodesy techniques devoted to geophysical and geodynamical purposes has recently evidenced some limitations due to the intrinsic Terrestrial Reference Frame (TRF) definition. Current TRFs are defined under hypotheses suited to overcome the rank deficiency of the observations with respect to the parameters that have to be estimated, i.e. coordinates and velocities (Dermanis, 2001; Dermanis, 2002). From a geodetic point of view, one possibility implies the application of the no-net-rotation condition (NNR). One of the main geophysical consequences due to the application of this condition is that it allows only accurate estimations of relative motions, whilst other motions of geodynamical interest, for instance with respect to the inner layers of the Earth body, are not determinable. The main purpose of this paper is to propose a unified way to describe plate motions, overcoming the problems introduced by the NNR condition, in order to establish a new reference frame useful for geodynamical applications too. Since we believe relevant the role played by global tectonics inferences, we introduce the concept of the main tectonic sinusoid to propose an analytical description of the plate motions flow, which is polarized to the “west” in the hotspot reference frame.160 271