Giuliano Panza

The modal summation technique is used to generate theoretical seismograms of the first 10 modes of Love and Rayleigh waves assuming PREM and IASPEI91 global Earth models and 288 focal mechanisms for each of the 15 source depths ranging between 0 and 600 km. On the basis of the results of previous research we consider a constant epicentral distance, equal to 4500 km. The amplitudes of 20+/-2 s waves are measured on each of the synthetic seismograms, and averaged for each of the depths yielding theoretical curves of amplitude vs. depth for all 3 considered components. In order to compare these results with observations, we use individual stations data on 20 s surface wave amplitudes for 515 earthquakes with focal depths up to 631 km, as reported in the ISC and NEIC bulletins. To enable comparison, all data are reduced to the same seismic moment and the same distance.

The two methodologies applied in this study develop the widely accepted concept that the lithosphere is built-up by different-scale blocks, separated by mobile boundaries. The aim of this work is to provide new insights about active deformations and to improve seismic hazard assessment in the Alps and surrounding areas. The Morphostructural Zonation method, MSZ (Alekseevskaya et al., 1977), allows for the identification of the sites capable of the strong events, while the block model of the lithosphere dynamics (Gabrielov et al., 1990) permits to generate a synthetic catalogue of earthquakes to be used for the analysis of some long-term features of seismic energy release in the modeled region.TRANSALP Conference (2003), Triest

We investigate the lithosphere-asthenosphere structure and the active tectonics along a stripe from the Tyrrhenian to the Adriatic with emphasis on the Umbria-Marche area by means of surface-wave tomography, and inversion studies for structure and seismic moment tensor retrieval. The data include seismic waveforms, a large compilation of local group velocities (0.8-4s) and regional phase and group velocity (10-100s) measurements.

An advanced modeling technique that allows us to compute realistic synthetic seismograms was used to create a database of realistic synthetic accelerograms in a set of selected sites in the Sofia urban area. The accelerograms can be used to assess the local site response in terms of the response spectra ratio (RSR). The results of this study, i.e. time histories,

The Horizontal-to-Vertical Spectral Ratio (HVSR) obtained from microtremor data recorded at three test sites are analyzed in order to highlight some issues related to the computation of the SESAME criteria that define the statistical robustness of possible peaks. In case of multiple-peak HVSR curves, it is shown that to properly assess the statistical properties of a peak and avoid the problem of multimodal data distribution, it is crucial to isolate each peak by reducing the frequency range around it. It is also shown that, while the standard approach used to obtain a homogeneous data set is represented by the removal of large-amplitude transient events before the computation of the HVSR, the removal of outlier HVSR curves can be a more effective way to obtain such a goal, being outlier HVSR curves not necessarily associated to large-amplitude transient events. It is eventually briefly discussed the problem of the proper management of multi-peak HVSR curves in microzonation studies while defining the so-called soil frequency maps. It is argued that to focus these maps just on the lowest-frequency (f0) value is questionable because higher-frequency peaks can be much more important when the local urban landscape is characterized by low-rise buildings.

Kosovo is one of the most seismically active regions in Europe, lying within the Alpine-Mediterranean tectonic belt. Historical records for the region show several catastrophic earthquakes with epicentral intensity IX (MCS). However, due to Kosovo’s high population density, high prevalence of traditional construction, and insufficient enforcement of building codes, Kosovo is vulnerable to earthquake damage. In this study, we present earthquake hazard maps for bedrock conditions in Kosovo based on the well-known Neo-deterministic Seismic Hazard Assessment (NDSHA) method. NDSHA relies upon the fundamental physics of wave generation and propagation in complex geologic structures to generate realistic time series, used as input for the computation of several ground motion parameters, integrating the available knowledge of seismic history, seismogenic zones and morphostructural nodes. In accordance with continuum mechanics, the tensor nature of earthquake ground motion is preserved, prod...

In this paper, we discuss a possible combination of Earthquake Early Warning (EEW) and Neo-deterministic Seismic Hazard Assessment (NDSHA), and propose a new warning model, EEW2.0. The aim is to provide a differentiated warning alert to various end-users based on the results of seismic hazard assessment evaluation. The implementation of such a system contains three basic steps: (a) classification of “potential to cause hazard” in terms of magnitude; (b) determination of the source areas and building a hazard database in terms of Modified Mercalli Intensity (MMI) maps, considering all possible earthquake scenarios in the source area, for the whole protected area; (3) equipping unique decision framework for specific end-users. When a damaging earthquake (M ≥ 5.0) is detected, EEW2.0 quickly matches the prepared MMI map by estimated magnitude and epicenter, then directly extracts the MMI value and issues an early warning to the public. With the great attention and resources put into th...

Several geodynamic processes and the lithosphere structural properties of the Central Mediterranean are still unknown and not yet completely understood. To make a step towards a better knowledge of the opening of the Tyrrhenian Basin, the subduction of the Ionian lithosphere in the Calabrian Arc and the migration of the back arc system of the Apennine chain, a fairly detailed structural model of the lithosphere-asthenosphere system (thickness, Sand P-wave velocities of the crust and of the uppermost mantle layers) has been defined for cells of 1°x1° in the Calabrian Arc region. This has been done with the non-linear inversion of local dispersion data, obtained from surface wave tomography. Available seismic and geological data derived from previous studies have been used as a priori and independent information. This study has allowed to identify a peculiar lithosphere with a very shallow Moho (less then 10 km deep) and a low Vs just below a very thin lid, in correspondence of the su...

Abstract A New Paradigm is needed for Reliable Seismic Hazard Assessment RSHA, not only from consideration of (a) the huge human losses experienced in the many recently destructive earthquakes worldwide; but also from (b) theoretical considerations of seismic wave generation and propagation phenomena through often non-homogeneous media within the earth's crust, particularly when large and more complex fault ruptures occur. The Neo-Deterministic Seismic Hazard Assessment (NDSHA) method, proposed some twenty years ago, is found to reliably and realistically simulate the wide suite of earthquake ground motions that may impact civil populations as well as their heritage buildings. The scenario-based NDSHA modeling technique is developed from comprehensive physical knowledge of: (i) the seismic source process; (ii) the propagation of earthquake waves; and (iii) their combined interactions with site effects. Thus, NDSHA effectively accounts for the tensor nature of earthquake ground motions: (a) formally described as the tensor product of the earthquake source functions and the Green's functions of the transmitting (pathway) medium; and (b) more informally described as mathematical arrays of numbers or functions (indices) “that transform according to certain rules under a change of coordinates.” Importantly, NDSHA therefore uses all available information about the spacial distribution of large magnitude earthquake phenomena, including: (a) Maximum Credible Earthquake (MCE) – which is based on seismic history and seismotectonics; and (b) geological and geophysical data. Thus it does not rely on scalar empirical ground motion attenuation models (GMPEs), as these are often both: (a) weakly constrained by available observations; and (b) fundamentally unable to account for the tensor nature of earthquake ground motions.

To obtain the shear velocity structure across North-West of Iran and surrounding areas to a depth of 160 km, we performed a namely Hedgehog nonlinear inversion on Rayleigh wave group velocity dispersion curves in the period range from 7 to 60 s. The distributed dispersion curves are the results of our surface wave dispersion tomography using the data of 280 local and regional seismic events, recorded by the medium- and broad-band seismic stations in the region. We outline different crust and upper mantle structures for the study area based on calculated group and shear velocities. Our results reveal relatively low velocities at the shorter periods (7–10 s) in the presence of sedimentary basins (e.g., South Caspian Basin) and for eastern Anatolia and relatively high velocities along the Sanandaj–Sirjan Metamorphic zone, Alborz, Talesh, and the Lesser Caucasus Mountains. By depth inversion of group velocities, we observed 14-km-thick sediments in South Caspian Basin and Kura Depression. Based on our maps at 20 s, we outline different crustal models for the region and highlight the differences between South Caspian Basin and NW Iran, on one side, and the similarities between the South Caspian Basin and Kura Depression that extend beneath Talesh, Alborz, and Lesser Caucasus, on the other. Comparing the shear velocity of lower crust in South Caspian Basin and Kura Depression with that of NW Iran proves different origination of lower crust in the basin, probably oceanic source, because of its significant higher shear velocity rather than NW Iran. In Talesh, we observe indications of an under-thrusting of the lower crust of SCB beneath NW Iran while the middle crust is locked. The analysis of group velocities at longer periods (≥ 35 s) and obtained shear velocity models allows us to outline different lithospheric structures and crustal depth in the region. The high group velocities in Talesh, South Caspian Sea, and Lesser Caucasus on one side and Zagros Folding and Thrust Belt on the other, beside the result of shear velocity models, suggest the presence of a stable and thick mantle lid that seems to be thin or absent in the eastern Anatolia and much of NW Iran. The shallowest Moho and Lithosphere Asthenosphere boundary depths of 37 and 63 km were observed in Eastern Anatolian Accretionary Complex. The thin mantle lid in this region has affected the whole crust in such a way that we observed the lowest shear velocities inside the crust in this region. We observed a significant thickening of both crust and lithosphere in Sanandaj–Sirjan Metamorphic zone comparing to Urmieh Dokhtar Magmatic Arc and Zagros Folding and Thrust Belt on its two sides.

SUNTO L'Accademia Nazionale dei Lincei ha avviato il progetto "I Lincei per una nuova didattica nella Scuola: una rete nazionale" con il fine di sostenere e favorire un miglioramento del sistema nazionale di istruzione e formazione, dando vita a una rete di istituzioni locali che imposti e promuova una rinnovata metodologia di insegnamento delle discipline scientifiche (scienze e matematica) e una didattica laboratoriale per un uso logico-argomentativo della lingua italiana. L'attività, che verrà svolta presso il Polo di Trieste coinvolgerà vari docenti dell'Università degli Studi di Trieste e sarà rivolta agli insegnanti delle scuole primarie e secondarie di I e II grado della regione Friuli Venezia Giulia. PAROLE CHIAVE

A New Paradigm (data driven and not like the currently model driven) is needed for Reliable Seismic Hazard Assessment RSHA. Neo-Deterministic Seismic Hazard Assessment (NDSHA) integrates earthquake geology, earthquake science, and particularly earthquake physics to finally achieve a New (and needed) Paradigm for Reliable Seismic Hazard Assessment RSHA.Although observations from many recent destructive earthquakes have all confirmed the validity of NDSHA’s approach and application to earthquake hazard forecasting-nonetheless damaging earthquakes still cannot yet be predicted with a precision requirement consistent with issuing a red alert and evacuation order to protect civil populations. However, intermediate-term (time scale) and middle-range (space scale) predictions of main shocks above a pre-assigned threshold may be properly used for the implementation of low-key preventive safety actions, as recommended by UNESCO in 1997. Furthermore, a proper integration of both seismological...

The Neo-Deterministic Seismic Hazard Assessment (NDSHA) method reliably and realistically simulates the suite of earthquake ground motions that may impact civil populations as well as their heritage buildings. The modeling technique is developed from comprehensive physical knowledge of the seismic source process, the propagation of earthquake waves and their combined interactions with site effects. NDSHA effectively accounts for the tensor nature of earthquake ground motions formally described as the tensor product of the earthquake source functions and the Green Functions of the pathway. NDSHA uses all available information about the space distribution of large magnitude earthquake, including Maximum Credible Earthquake (MCE) and geological and geophysical data. It does not rely on scalar empirical ground motion attenuation models, as these are often both weakly constrained by available observations and unable to account for the tensor nature of earthquake ground motion. Standard N...

This study defines a 3D shear-wave velocity model to the depth of about 350 km in the region of Balkan Peninsula by application of several methods and tools: collection of surface-wave dispersion measurements; tomography on a grid sized 1 degree by 1 degree; non-linear inversion of dispersion relations; local smoothing optimization; and juxtaposition of representative cellular models. This study upgrades, refines and extends the results obtained for the region by Raykova and Panza (2006), Raykova and Nikolova (2007), Panza et al. (2007) and Brandmayr et al. (2010).

Velocity structure of the lithosphere-asthenosphere system, to the depth of about 350 km, is obtained for almost 400 cells, sized 1 degree by 1 degree in the Mediterranean region. The models are obtained by the following sequence of methods and tools: surface-wave dispersion measurements and collection; 2D tomography of dispersion relations; non-linear inversion of cellular dispersion relations; smoothing optimization method to select a preferred model for each cell. The 3D velocity model, that satisfies Occam razor principle, is obtained as a juxtaposition of selected cellular models. The reconstructed picture of the lithosphere-asthenosphere system evidences the, globally well known, asymmetry between the W- and E-directed subduction zones, attributed to the westward drift of the lithosphere relative to the mantle. Different relationship between slabs and mantle dynamics cause strong compositional differences in the upper mantle, as shown by large variations of seismic waves veloc...

Il particolare interesse dell'Accademia Nazionale dei Lincei per il mondo della scuola nei suoi aspetti educativi e di aggiornamento, trova un significativo ed esemplare interesse complementare nella decisione della Provincia di Trieste di realizzare il programma di verifiche sismiche sugli edifici di sua competenza, tra cui gli edifici scolastici, secondo criteri che superano quelli minimi e non sufficientemente affidabili previsti dalla normativa 1. Mentre sulle iniziative promosse dall'Accademia Nazionale dei Lincei mi soffermerò nel mio successivo intervento, nel porgervi il mio indirizzo di saluto, ritengo opportuno richiamare la vostra attenzione su alcune recenti decisioni operative adottate per la sicurezza degli edifici scolastici. È ormai da più di cinque anni che prosegue la collaborazione tra la Provincia di Trieste e il team di ricerca dello scrivente, operante nell'ambito del Dipartimento di Matematica e Geoscienze dell'Università degli Studi di Trieste...

over the thick alluvium of the Bengal Basin, where it lies at the boundary of the zone III and zone IV of the seismic zonation map of India. An example of the study of site effects of the metropolitan Kolkata is presented based on theoretical modeling. Full synthetic strong motion waveforms have been computed using a hybrid method that combines the modal summation and finite difference techniques. The 1964 Calcutta earthquake, which was located at the southern part of Kolkata, is taken as the source region, with the focal mechanism parameters of dip = 32, strike = 232 and rake = 56. Four profiles are considered for the computation of the synthetic seismograms from which the maximum ground acceler-ation (AMAX) is obtained. Response spectra ratios (RSR) are then computed using a bedrock reference model to estimate local amplifications effects. The AMAX varies from 0.05 to 0.17 g and the comparison of the AMAX with the different intensity scales (MM, MSK, RF and MCS) shows that the exp...

Similar to Båth’s law, which points that the difference in magnitude between the main shock and its largest aftershock is generally about 1.2, the Panza- Rugarli law states that for MCE, the design magnitude Mdesign, can be set, given the current state of knowledge, equal to the sum of Mmax and 0.7, and it is an intriguing topic for further discussion.

Institute of Geophysics, CEA, Beijing, China - Beijing University of Civil Engineering and Architecture, Beijing, China - Academia Nazionale dei Lincei, Italy - Accademia Nazionale delle Scienze detta dei XL, Rome, Italy. Earthquakes occur in a seemingly random way and in some cases it is possible to trace seismicity back to the concept of deterministic chaos. Therefore, seismicity, apparently, can be explained by a deterministic mechanism that arises as a result of various convection movements in the Earth’s mantle, expressed in the modern movement of lithospheric plates fueled by tidal forces. The polarized plate tectonics and the complex nature of seismic phenomena highlight the need to avoid the use of overly simplistic models, particularly for the assessment of the risks associated with earthquakes. An earthquake compatible with the seismogenic characteristics of a certain area, even if sporadic and therefore labeled as “unlikely,” can occur at any time. The anti-seismic design parameters must consider the magnitude values defined according to the seismic history and seismotectonics, as done with the Neo-Deterministic Seismic Hazard Assessment (NDSHA) approach. NDSHA is the innovative multi-disciplinary scenario-physics-based approach, launched at the turn of the millennium, for the evaluation of seismic hazard and risks. When an earthquake occurs, the ground shaking does not depend on its likelihood according to the widespread Probabilistic Seismic Hazard Analysis (PSHA), formulated ignoring plate tectonics, whose estimates are too often wrong. An “unlikely” earthquake can occur at any time and, sooner or later, with 100% probability.Noting the fluctuation in specified design values that occurs from code edition to code edition, structural engineers have expressed disbelief in the validity of the science upon which the maps are based and dissatisfaction with the ever-changing design requirements for buildings. Importantly, the maps portray precision in the design values that is inappropriate, given the substantial uncertainty in the values portrayed. The legislation hence should be based on NDSHA approach, able to overcome most of, if not all, the obvious limitations and serious misconceptions of other prevailing approaches. Performing a comprehensive and homogeneous assessment by NDSHA of the seismic hazard in the countries crossed by Belt & Road appears to be a must in view of the proven fallacy of PSHA approaches such as GSHAP and the easily predictable failures of its legacy as GEM.From a safety standpoint, it is essential that infrastructures and public installations are designed to resist future strong earthquakes. NDSHA has proven to both reliably and realistically simulate comprehensive sets of hazardous ground motions in many regions worldwide and is gaining momentum in spreading worldwide an innovative Paradigm of Reliable Seismic Hazard Assessment (RSHA) that should ultimately change mind-sets of scientific and engineering communities from disbelief in probabilistic forecasting to optimistic challenging issues of neo-deterministic predictability of Natural Hazards and Risks.The relevance and topicality of the problem of a reliable estimate of seismic hazard is evidenced by Menyuan M6.9 earthquake occurred on Jan. 8 (Beijing Time) 2022. As a consequence, the Sino-European railway was affected by some destructions that prevented the railway from running on normal schedule. Seismic safety of such railways is shown to be an important issue in the B&R region and I guess that NDSHA may contribute significantly and reliably to it. In this perspective I would like to propose that a joint AfSC & ASC working group is established.

PSHA, the traditional probabilistic approach is not scientific in its nonfalsifiable formulation and unsatisfactory in its practical applications.
Better to retire and then bury PSHA, which is more concept and “trust in numbers” than it is a tested pathway to seismic safety, R.I.PSHA . . . than to “take a chance on a guess” and then, in the future, to experience more earthquake disasters and catastrophes, because erroneous hazard maps depicted only “low hazard”, but the active tectonic regions again acted otherwise!

Predicting earthquakes and their effects is still a very difficult task due to the nonlinear behaviour of the earth system. Although we have made some progress in the last decade with the well-known Neo Deterministic Seismic Hazard Assessment (NDSHA). Predicting climate is as difficult as predicting earthquakes and therefore I am hesitant to accept mainstream climate predictions that foresee climate doom in the future. This is the reason that prompted me to accept the request to sign, as leading light of NDSHA, the CLINTEL Global Climate Declaration. In other words, I felt it my duty to demonstrate how fundamental drawbacks affect different branches of science that are apparently very distant from each other.