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Del Pezzo, Edoardo
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Preferred name
Del Pezzo, Edoardo
Email
edoardo.delpezzo@ingv.it
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staff
ORCID
Researcher ID
A-7492-2011
153 results
Now showing 1 - 10 of 153
- PublicationOpen AccessANNALS OF GEOPHYSICS: AD MAJORA(2014)
; ; ; ; ; ; ; ; ; ;Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Bianco, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;De Michelis, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Masina, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Muscari, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Caprara, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Chiodetti, A. G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Gresta, S.; Univ Catania; ; ; ; ; ; ; ; Annals of Geophysics (ISSN: 1593-5213; from 2010, 2037-416X) is a bimonthly international journal, which publishes scientific papers in the field of geophysics sensu lato. It derives from Annali di Geofisica (ISSN: 0365-2556), which commenced publication in January 1948 as a quarterly periodical devoted to general geophysics, seismology, Earth magnetism, and atmospheric studies....1541 255 - PublicationRestrictedTwo-dimensional seismic attenuation images of Stromboli Island using active data(2015-02)
; ; ; ; ; ;Prudencio, J.; Instituto Andaluz de Geofisica, Universidad de Granada ;Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Ibanez, J. M.; Instituto Andaluz de Geofisica, Universidad de Granada ;Giampiccolo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Patane, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; ; ; ; In this work we present intrinsic and scattering seismic attenuation 2-D images of Stromboli Volcano. We used 21,953 waveforms from air gun shots fired by an oceanographic vessel and recorded at 33 inland and 10 ocean bottom seismometer seismic stations. Coda wave envelopes of the filtered seismic traces were fitted to the energy transport equation in the diffusion approximation, obtaining a couple of separate Qi and Qs in six frequency bands. Using numerically estimated sensitivity kernels for coda waves, separate images of each quality factor were produced. Results appear stable and robust. They show that scattering attenuation prevails over intrinsic attenuation. The scattering pattern shows a strong concordance with the tectonic lineaments in the area, while an area of high total attenuation coincides with the zone where most of the volcanic activity occurs. Our results provide evidence that the most important attenuation effects in volcanic areas are associated with the presence of geological heterogeneities.293 24 - PublicationOpen AccessUnderstanding seismic path biases and magmatic activity at Mount St Helens volcano before its 2004 eruption(2020-04-01)
; ; ; ; ; ; ; In volcanoes, topography, shallow heterogeneity and even shallow morphology can substan- tially modify seismic coda signals. Coda waves are an essential tool to monitor eruption dynamics and model volcanic structures jointly and independently from velocity anomalies: it is thus fundamental to test their spatial sensitivity to seismic path effects. Here, we apply the Multiple Lapse Time Window Analysis (MLTWA) to measure the relative importance of scattering attenuation vs absorption at Mount St Helens volcano before its 2004 erup- tion. The results show the characteristic dominance of scattering attenuation in volcanoes at lower frequencies (3–6 Hz), while absorption is the primary attenuation mechanism at 12 and 18 Hz. Scattering attenuation is similar but seismic absorption is one order of magnitude lower than at open-conduit volcanoes, like Etna and Kilauea, a typical behaviour of a (rela- tively) cool magmatic plumbing system. Still, the seismic albedo (measuring the ratio between seismic energy emitted and received from the area) is anomalously high (0.95) at 3 Hz. A radiative-transfer forward model of far- and near-field envelopes confirms this is due to strong near-receiver scattering enhancing anomalous phases in the intermediate and late coda across the 1980 debris avalanche and central crater. Only above this frequency and in the far-field diffusion onsets at late lapse times. The scattering and absorption parameters derived from MLTWA are used as inputs to construct 2-D frequency-dependent bulk sensitivity kernels for the S-wave coda in the multiple-scattering (using the Energy Transport Equations—ETE) and diffusive (AD, independent of MLTWA results) regimes. At 12 Hz, high coda-attenuation anomalies characterize the eastern side of the volcano using both kernels, in spatial correla- tion with low-velocity anomalies from literature. At 3 Hz, the anomalous albedo, the forward modelling, and the results of the tomographic imaging confirm that shallow heterogeneity beneath the extended 1980 debris-avalanche and crater enhance anomalous intermediate and late coda phases, mapping shallow geological contrasts. We remark the effect this may have on coda-dependent source inversion and tomography, currently used across the world to image and monitor volcanoes. At Mount St Helens, higher frequencies and deep borehole data are necessary to reconstruct deep volcanic structures with coda waves.54 20 - PublicationRestrictedIntermediate-focus earthquakes under South Shetland Islands (Antarctica)(1997)
; ; ; ; ; ; ;Ibanez, J.; University of Granada, Spain ;Morales, J.; University of Granada, Spain ;Alguacil, G.; University of Granada, Spain ;Almendros, J.; University of Granada ;Ortiz, R.; CSIC Madrid ;Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ; Intermediate-focus seismicity (50192 22 - PublicationRestrictedJoint observation of coherent coda waves at surface and underground arrays(2013-04-16)
; ; ; ; ;La Rocca, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Galluzzo, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Scarpa, R.; Università di Salerno; ; ; Local and regional seismicity jointly recorded by two dense small aperture arrays, one installed at surface and one at 1.3 km depth, constitutes an interesting data set useful for coda observations. Applying array techniques to earthquakes recorded at the two arrays we measure slowness, backazimuth and correlation coefficient of the coherent coda wave signals in five frequency bands in the range 1–10 Hz. Slowness distributions show marked differences between surface and underground, with slow signals at surface (slowness greater than 1.0 s km−1) that are not observed underground. We interpret these coherent signals as surface waves produced by the interaction of body waves with the free surface characterized by rough topography. The backazimuth values measured in the frequency bands centred at 1.5 and 3 Hz are almost uniformly distributed between 0 and 360◦, while those measured at higher frequencies show different distributions between surface and underground. On the contrary, the earthquake envelopes show very similar coda shapes between surface and underground recordings, with an almost constant coda-amplitude ratio (between 4 and 8) in a wide frequency range.243 25 - PublicationOpen AccessFirst 2-D intrinsic and scattering attenuation images of Mt Etna volcano and surrounding region from active seismic data(2020)
; ; ; ; ; ; ; ; ;; ; ; ; We present 2-D attenuation images of the Mt Etna volcanic region on the basis of separation of intrinsic and scattering effects. The analysis presented here exploits a large active seismic database that fully covers the area under study. We observe that scattering effects dominate over intrinsic attenuation, suggesting that the region is very heterogeneous. Comparison with analyses conducted at other volcanoes reveals that the Mt Etna region is characterized by high intrinsic attenuation, resulting from the presence of large volcanoclastic deposits at shallow depth. The 2-D distributions of intrinsic and scattering anomalies show the presence of regions characterized by high and low attenuation effects, corresponding to several tectonic and volcanic features. In particular, we identify a high attenuation region in the SW sector of the Mt Etna volcanic complex, which is correlated with high seismicity rates and volcanism. This work supports the hypothesis of a link between the dynamics of the SW flank and the recharge of the volcano in the last decades, occurring under the summit crater and, secondarily, the upper South rift zone.1489 123 - PublicationOpen AccessShear wave splitting time variation by stress-induced magma uprising at Mount Etna volcano(2006-05-24T13:19:55Z)
; ; ; ; ;Bianco, F.; Istituto Nazionale Geofisica e Vulcanologia , Osservatorio Vesuviano, Napoli. ;Scarfì, L.; Istituto Nazionale Geofisica e Vulcanologia Sez. Catania ;Del Pezzo, E.; Istituto Nazionale Geofisica e Vulcanologia , Osservatorio Vesuviano, Napoli. ;Patanè, D.; Istituto Nazionale Geofisica e Vulcanologia Sez. Catania; ; ; Shear wave splitting exhibits clear time variations before the July 17th – August 9th, 2001 flanK eruption at Mount Etna. The normalized time delays, Tn, detected through an orthogonal transformation of singular value decomposition, exhibit a clearincrease starting 20 days before the occurrence of the eruption (July 17th); the qS1 polarization direction, obtained using a 3D covariance matrix decomposition, shows a 90°-flip several times during the analyzed period: the last flip 5 days before the occurrence of the eruption. Both splitting parameters also exhibit a relaxation phase shortly before the starting of the eruption. Our observations seem in agreement with Anisotropic Poro Elasticity (APE) modelling, suggesting a tool for the temporal monitoring of the build up of the stress leading to the occurrence of the 2001 eruption at Mt. Etna.165 417 - PublicationRestrictedMathLTWA: Multiple lapse time window analysis using Wolfram Mathematica 7(2010)
; ; ;Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Bianco, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; The MATHCAD 2000 professional code to perform the Multiple Lapse Time Analysis (MLTWA) has been revised and rewritten in MATHEMATICA 7. The new code contains two new procedures to find the minimum of the misfit function between observation and model and a new example of application to real data from Chamoli earthquake aftershock sequence237 46 - PublicationRestrictedRete Mobile e Laboratorio Analisi aVanzate (LAV) - Rendiconto 2013(2014-03)
; ; ; ; ; ; ; ;Cusano, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Galluzzo, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;La Rocca, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Petrosino, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Bianco, F. ;Castellano, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ;; In the text262 94 - PublicationOpen AccessSEISMIC WAVEFIELD ARRAY PROCESSING ANALYSIS USING WAVELET COHERENCE(2005-12-09)
; ; ; ;Nisii, V.; OSSERVATORIO VESUVIANO (I.N.G.V.) NAPOLI ;Saccorotti, G.; OSSERVATORIO VESUVIANO (I.N.G.V.) NAPOLI ;Del Pezzo, E.; OSSERVATORIO VESUVIANO (I.N.G.V.) NAPOLI; ; Volcanic signals are one of the most difficult subject of study for seismologists. The lack of clear body-wave phase arrivals and the rapid loss of signal coherence with distance make generally impossible application of traditional location techniques based on travel times inversion. Overthe past ten years,however,the wides pread application of multichannel techniques hasal lowed forrobust and reliable locations of these signals over abroad range of frequencies. Consequent to the largely increased computing capabilities, array processing in Volcano Observatories is now developing to ward thereal-time detection and tracking of volcanic sources. However,the energy of volcanic signals may spread over abroad frequency interval(Fig.1).The successful detection and measurement of these signals requirest herefore subsequent band-pass filtering operations, and exact tayloring of the time window lengthsto the central frequency of each filter. Exploting the localisation properties of Continuos Wavelet Transforms (CWT)in the time and frequency /scaledomains,in this workweuse multichannel Wavelet Coherence (WCO)toperform signal detection from local correlation information. For the time/scale regions of high multichannel coherence, wethenextend the MUltiple Signal Classification (MUSIC) methodto the spatial covariance matrice sobtained from the complex-valued wavele tcoefficient timeseries127 176