bluuebunny/crossref_metadata_2025 huggingface dataset:
A finite-element numerical approach for modeling tsunamis
Authors: S. Tinti  , I. Gavagni  , A. Piatanesi
Published: June 2021

A numerical scheme suitable for modeling tsunamis is developed and tested against available analytical solutions. The governing equations are the shallow water nonlinear nondispersive equations that are known to be appropriate for tsunami generation and propagation in coastal waters. The integration scheme is based on a finite-element space discretization, where the basic elements are triangles and the shape functions are linear. The time integration is a double step algorithm that is accurate to the second order in the time step ?t. The boundary conditions are pure reflectivity and complete transmissivity on the solid and open boundaries respectively and are implemented by modifying the time integration scheme in a suitable way. The model performance is evaluated by comparing the results with the analytical solutions in selected cases and is quite satisfactory, even when the grid has a coarse spatial resolution.
The Working Group III on data exchange
Authors: B. Dost
Published: June 2021

n 1993 the ORFEUS Data Center (ODC; Dost, 1991) changed hosting organisation. It moved within the Netherlands from the University of Utrecht to the Royal Netherlands Meteorological Institute (KNM1) in de Bilt. This change in hosting organisation was necessary to ensure a longer term stability in the operation of the ODC. Key issues for the ODC are the rapid on-line data access and quality controlled, complete and efficient off-line data access. During 1992 the ODC became the European node in the international SPYDER system which provides near real-time access to digital broadband data from selected high quality stations. Electronic messages trigger soveral centers well distributed over the globe. These centers then collect the data by modem from selected stations in their region. Finally, data are distributed between data centers over internet.
The FDSN Archive at the IRIS Data Management Center
Authors: T. Ahern
Published: June 2021

In August of 1990, the IRIS Data Management Center (IRIS DMC) was designated as the first FDSN Data Center. Since that time the IRIS DMC has also come to be known as the FDSN Archive. As the FDSN Archive, all member networks, through their own local Network Data Centers, routinely send data to the IRIS DMC. At the present time we have received data from seven member networks. These include: CNSN (Canada); CDSN (China); GEOSCOPE (France); Graefenberg (Germany); IRIS GSN (U.S.A.); MEDNET (Italy); POSEIDON (Japan). In addition to acting as the FDSN Archive, the IRIS DMC is responsible for archiving and distributing data from several sources. The Global Seismographie Network (GSN) and the Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL) and the Joint Seismic Program (JSP) are three IRIS programs that presently send data to the IRIS DMS. The DMC also archives data from some regional networks in the United States and in the Former Soviet Union (FSU). The DMC is one component of a larger Data Management System (DMS) consisting of several components including two Data Collection Centers (DCCs), one Data Management Center (DMQ, a DMC Host at the University of Washington, a Wave form Quality Center (WQC), and the Moscow Data Analysis Center (MDC) in Russia.
A new approach for three component seismic array processing
Authors: O. K. Kedrov  , V. E. Permyakova
Published: June 2021

The new concept and methodology of regional seismic arrays (RSA) equipped by three component (3 C) sensors (Z, NS, EH9, are proposed. Such system could be more perfect tool of Earth interior investigations. This aim can be achieved by introduction of polarization filtering of 3 C seismic vibrations as an effective means of noise suppression and robust detection and identification of secondary body phases of the signals. The proposed algorithm is based on: 1) linear phase band pass frequency filtering of N 3 C records in M bands; 2) polarization filtering of all 3 C records in all L directions where array beams are routinely oriented; 3) calculation of L beams in M bands using polarized P, SV and SH traces of individual sensors; 4) detection of signals on the L*M P, SV and SH traces; 5) location of the event. The main new procedures are 2) and 3). Due to these new approaches the procedures 4) and 5) will be improved in comparison with,those routinely used today at RSA's. This work includes the theoretical consideration of proposed method efficiency and preliminary experimental results.
Comparison between LDG-network and GERESS-array with respect to regional detection and location results
Authors: H. P. Harjes  , B. Massinon  , Y. Ménéchal  , H. Schulte-Theis
Published: June 2021

The design of a global seismic system to monitor compliance with a ban on underground nuclear testing considerably deviates from previous concepts of international seismic data exchange. The new concept relies on centralized processing of continuous data from a fixed station network (alpha stations) which provides the primary detection and location capability. This alpha station network is augmented by additional stations (beta stations) which send data on request to refine the hypocentres of events which were detected by the alpha network. To test this concept we have used the GERESS array in Germany as a prototype alpha station and investigated its regional detection and location capability for events in France and surrounding areas. For this region, data from the national French network operated by LDG provide an excellent reference data base. Within a 5 degree distance, GERESS showed an excellent performance in terms of detection and location down to magnitude M(LDG) = 3. Between a 5 degree and 10 degree distance, the detection capability is still high but very often it is not sufficient to locate events below M(LDG) = 4. Generalizing these results, we can conclude that either the maximum distance between alpha stations should be 10 degrees or the contribution of beta stations has to play a significant role in a future monitoring system.
Lithospheric structure models applied for locating the Romanian seismic events
Authors: M. Rizescu  , E. Popescu  , V. Oancea  , D. Enescu
Published: June 2021

The paper presents our attempts made for improving the locations obtained for local seismic events, using refined lithospheric structure models. The location program (based on Geiger method) supposes a known model. The program is run for some seismic sequences which occurred in different regions, on the Romanian territory, using for each of the sequences three velocity models: 1) 7 layers of constant velocity of seismic waves, as an average structure of the lithosphere for the whole territory; 2) site dependent structure (below each station), based on geophysical and geological information on the crust; 3) curves deseribing the dependence of propagation velocities with depth in the lithosphere, characterizing the 7 structural units delineated on the Romanian territory. The results obtained using the different velocity models are compared. Station corrections are computed for each data set. Finally, the locations determined for some quarry blasts are compared with the real ones.
ear real time estimation of magnitudes and moments for local seismic events
Authors: C. D. Mendi  , E. S. Husebye
Published: June 2021

The general Popularity of magnitude as a convenient and robust measure of earthquake size makes it tempting to examine whether this parameter can be reliably estimated in near real time. In this study we dernonstrate that this is indeed the case conditioned on the design of the signal detector being of STA/LTA type where STA is a short term signal power or rms estimate. Using real data we dernonstrate the Random Vibration Theory relation that Amax (21nN) 1/2 Arms , is valid for non stationary seismic signals. Using Rayleigh's theorem we also estabmlaixshed a relation brmetween Arms and the flat portion of the source spectra. These Amax and Arms estimation procedures are used for determining conventional magnitudes and moment magnitudes for 29 events as recorded by the Norwegian Seismograph Network (NSN). We used here a procedure outlined by Sereno et al. (1988) and also their geometrical spreading and attenuation parameters derived from analysis of NORSAR recordings. Our magnitude and moment magnitude estimates for 5 different frequency bands are in good agreement with the ML estimates derived from the conventional magnitude formulas in combination with empirical correction tables. Surprisingly, the Amax and Arms magnitudes produced consistent negative biased by ca. 0.4 units estimates even in the extreme 4 8 Hz band. In view of the good agreement between various types of magnitude estimates, we constructed conventional magnitude correction tables spreading and attenuation parameters from Sereno et al (1988) for a variety of signal frequency bands. Near real time Amax ad/or Arms or correspondingly event magnitudes would be of significance in automatic phase association analysis, bulletin production for local and regional seismic networks and the earthquakes monitoring performances of such networks.
ROSE: a high performance oblique ionosonde providing new opportunities for ionospheric research
Authors: P. C. Arthur  , P. S. Cannon
Published: June 2021

A high quality high frequency (HF) oblique ionosonde has been developed for use in propagation research and associated studies of the ionosphere. The ionosonde is known as ROSE (radio oblique sounding equipment) and requires the connection of a specially designed enhancement to a commercially available chirp sounder receiver (RCS-5) manufactured by the BR Corporation in the U.S.A. Two important features are brought about by the addition of this enhancement. Firstly, an increase in the resolution of an ionogram by a factor of approximatety three. This allows the fine structure in the ionospheric returns to be detected. Secondly, colour coding of the ionogram according to the amplitude of the received signal. Detailed mode amplitude information and comparisons of the relative strengths of propagating modes can be achieved through this. Additional features which are provided include display handling, data storage and off-line analytical facilities. This paper describes the system architecture of ROSE, its main features and its application to ionospheric research.
Further study of fOF2 and M(3000)F2 in different solar cycles
Authors: P. A. Bradley
Published: June 2021

Measured monthly median fOF2 and M(3000)F2 for Slough over six solar cycles from 1932 onwards are examined for a selection of hours and months. Data are shown as a function of twelve-monthly smoothed sunspot number. Comparisons are made for the different solar cycles and for the rising and falling halves of each cycle. Measurements for individual cycles are compared with best-fit parabolic regression lines over all cycles to investigate possible systematic long-term effects.
Preliminary results on the ionospheric structure at dawn time observed during HRIS campaigns
Authors: P. Dominici  , C. Bianchi  , L. R. Cander  , G. De Franceschi  , C. Scotto  , B. Zolesi
Published: June 2021

Several campaigns of ionospheric vertical soundings with short-time interval between them (HRIS) have been recently performed at the ionospheric station in Rome. Some preliminary results concerning periods around local sunrise are presented. A cIear fading effect, due to the defocusing phenomena in the upper ionosphere, has been observed in different seasons
Structural and hydrogeological features of Pleistocene shear zones in the area of Rome (Central Italy)
Authors: C. Faccenna
Published: June 2021

The last tectonic episode observed in the Latium Tyrrhenian margin (Central Italy), few km cast of Rome, is represented by a set of middIe-upper Pleistocene N-S shear zones, characterised by complex geometric and kinematic setting. The easternmost of these shear zones displays a strike-slip component of motion and is located at the boundary between the Apennine carbonate chain and the volcanic areas. The distribution of travertine deposits and hydrothermal springs suggests that this fault zone acts as an impermeable barrier for lateral flow derived from superficial karstic circuit, and as a preferential upwelling surface for deep hydrothermal fluids. We propose that high fluid pressure could develop inside these fault zones favouring the reactivation of buried pre-existing crustal discontinuities and the local re-orientation of the stress field, as testified by the geometry and the kinematics of the surface fault pattern.
Non-chaotic emplacements of trench-arc zones in the Pacific Hemisphere
Authors: G. Scalera
Published: June 2021

It is shown how shape between certain ocean basins and continents create serious difficulties to the concept of subduction and can be considered evidence of a non-chaotic emplacement of the arc-trench zones along pre-existing deep geofractures, which are related to shapes of far continents. These similarities point to a fundamental process which cannot be described by the plate tectonics and other tectonic hypotheses, and which is till now mostly hidden to our understanding. Because the similarities are also clues of a former proximity of the circumpacific continents, an expanding earth appears favoured by this new observational evidence.
Discrimination between natural earthquakes and nuclear explosions using the Aswan Seismic Network
Authors: R. M. Kebeasy  , A. I. Hussein  , S. A. Dahy
Published: June 2021

There are many seismological differences between earthquake and nuclear explosions, but not all of them are observable at large distances or are applicable to every earthquake and explosion. Several discriminations have been checked using the Aswan Seismic Network (ASN) data. Data of 66 earthquakes and 42 presumed underground explosions which occurred in different regions of China, the U.S.S.R., India, Iran, Turkey and recorded at ASN were collected. All data were selected from the NEIC catalogue and EDR reports. It was found that mb: Msas well as mb(1 Hz): mb (2 Hz) work well for events with mb larger than 4.0 from data observed at ASN and obtained from the NEIC catalogue.
A project for a new alkali vapour magnetometer, optically pumped by a diode laser
Authors: N. Beverini  , O. Faggioni  , C. Carmisciano  , E. Alzetta  , E. Maccioni  , M. Francesconi  , A. Donati  , E. Simeone  , F. Strumia
Published: June 2021

We present here a project for the industrial development of a new magnetometer that is intended to achieve the highest performance in measuring geomagnetic field. The instrument is based on the well-known technology of optically pumped alkali vapour magnetometers. Unlike current commercial models, a diode laser replaces the traditional radio-frequency lamp as pumping source and our magnetometer uses potassium as reference atom, contrary to the more traditional cesium or rubidium. The advantages of this choice are discussed. Preliminary experimental results on a prototype show an expected accuracy better than 1 pT/Hz-1/2.
Position and spatial orientation of magnetic bodies from archaeological magnetic surveys
Authors: S. Piro  , S. Samir  , L. Versino
Published: June 2021

For the last twenty years magnetic surveys have frequently been applied in archaeological prospection. Among the different processing techniques that can be applied to the magnetic data, we studied the possibility for delineating the position and the spatial orientation of shallow depth magnetic anomalous bodies. The approach namely cross-correlation filter (or matched filter) has been adopted. At first, theoretical magnetic anomalies of total magnetic field, of its components and the vertical gradient of these, due to three-dimensional bodies, oriented S-N, E-W and NW-SE, were calculated. These synthetic bodies were considered a sum of many elementary prisms. Field measurements were simulated adding a noise component with different signal-to-noise ratio on the theoretical anomalies. In order to improve signal-to-noise ratio and to locate and delineate the orientation of the anomalous bodies a bidimensional cross-correlation technique was applied. Different synthetic anomalies, due to bodies with different dimensions, depths, susceptibility contrasts and geomagnetic parameters were used, as operators, to apply the cross-correlation technique. The efficiency of the method was improved using a normalised cross-correlation of the field data.
Magnetotelluric and DC electrical soundings in the Po plain (Veneto region)
Authors: L. Alfano  , M. Giudici  , A. Zaja
Published: June 2021

Eleven MT soundings and two dipole-dipole electrical soundings were carried out in the area of the Po plain south of the town of Padua. MT soundings were performed in the frequency band from 100 to 1/64 Hz; DC soundings were achieved, respectively, with a 2000 and 4000 m length of the array. The electrical interpretative models show a predominant monoclinalic tectonic behaviour with an evident deepening of the resistive basement to ward NE. The joint use of the two electrical techniques defined the geological and structural setting up to a depth of 2 km in a highly conductive area.
The ocean wave dynamo: a source of magnetic field fluctuations
Authors: J. Watermann  , A. Magunia  , M. Gambetta  , E. Bozzo
Published: June 2021

The alternating magnetic dynamo field of sea surface waves, a consequence of their Lorentz electric field, has been observed with a pair of simultaneously operated, closely spaced tri-axial magnetometers. Measurements from a magnetometer located in the centre of a tiny, uninhabited island served to compensate measurements from a near-shore magnetometer for magnetic pulsations of ionospheric origin, leaving the ocean wave dynamo field, effective close to shore only, as the dominant residual magnetic field. Amplitude and frequency of waves and swell were recorded with a vertical accelerometer (wave rider buoy) floating nearby on the sea surface. A spectral analysis was performed on ten nighttime intervals of three hours length each, and for every interval, the peak power of the surface waves (obtained from the wave rider) was compared with the peak power of the residual horizontal magnetic field (after the background field had been removed). The results suggest that the dual-sensor magnetic field observations yield, within the limits of statistical significance, a good quantitative description of the amplitude and frequency of sea surface waves and swell.
Electrical resistivity tomography investigations in the ufita Valley (southern Italy).
Authors: A. Giocoli  , C. Magrì  , P. Vannoli  , S. Piscitelli  , E. Rizzo  , A. Siniscalchi  , P. Burrato  , C. Basso  , S. Di Nocera
Published: June 2021

Several Electrical Resistivity Tomography (ERT) surveys have been carried out to study the subsurface structural and sedimentary settings of the upper Ufita River valley, and to evaluate their efficiency to distinguish the geological boundary between shallow Quaternary sedimentary deposits and clayey bedrock characterized by moderate resistivity contrast. Five shallow ERTs were carried out across a morphological scarp running at the foot of the northeastern slope of the valley. This valley shoulder is characterized by a set of triangular facets, that some authors associated to the presence of a SW-dipping normal fault. The geological studies allow us to interpret the shallow ERTs results obtaining a resistivity range for each Quaternary sedimentary deposit. The tomographies showed the geometrical relationships of alluvial and slope deposits, having a maximum thickness of 30-40 m, and the morphology of the bedrock. The resistivity range obtained for each sedimentary body has been used for calibrating the tomographic results of one 3560m-long deep ERT carried out across the deeper part of the intramountain depression with an investigation depth of about 170 m. The deep resistivity result highlighted the complex alluvial setting, characterized by alternating fine grained lacustrine deposits and coarser gravelly fluvial sediments.
Paleomagnetism of the Caldwell lavas, Eastern Townships, Québec.
Authors: M. K. SEGUIN
Published: June 2021

Forty two oriented samples (97 specimens) were obtained from 17
sites in metavolcanic rocks from the Caldwell Group of the Appalachians
of Southern Québec (longitude: 71u00'-71"30' W, latitude: 46°00'-46"10'N).
These metavolcanics of Lower Cambrian age are massive or pillowed lavas
of andesitic and mainly basaltic composition metamorphosed to the
sub-greenschist facies. Magnetite and occasionally hematite are the frequent
magnetic memory carrier.
In order to obtain some pertinent information relative to the stability
of the remanent magnetization component, stepwise alternating field
demagnetization was conducted on 35% of the specimens and the others
were demagnetized at an optimum alternating field. After AF treatment,
the paleopole position of the tilted formation from 16 localities is 148°E,
43°N (dp=11.3°, dm = 22.4°). After omission of 3 localities for which
a95>30°, the new paleopole position obtained is 173°E, 26°N. This formation
of Early Cambrian age is characterized by a reversed polarity.
Reappraisal of effective elastic thickness in the south-west Indian Ocean, and its possible implications
Authors: Deshraj Trivedi  , Tanmay K. Maji  , Debashish Sengupta  , Rajesh R. Nair
Published: June 2021

The bathymetry of the south-west Indian Ocean is dominated by three mid-oceanic ridge systems: the Chagos–Laccadives Ridge, the Central Indian Ridge, and the Mascarene Plateau. Although there have been a number of geophysical and geological investigations over the region, the genesis of these morphological features is still contradictory. Most of the estimations of effective elastic thickness in this region have been carried out in the spectral domain, either by transfer function analysis or by free-air admittance analysis. As these investigations were along some one-dimensional profiles or discrete blocks, spatial variation of the effective elastic thickness was not achieved. Here, we reappraise the estimation of effective elastic thickness in the south-west Indian Ocean by performing the computation in the spatial domain using flexure inversion. During this process, we also estimate the Moho depth throughout the region by two independent processes: gravity inversion, and flexural inversion. The Te values (effective elastic thickness) are estimated in the spatial domain, which match well with the results in the spectral domain obtained with the free-air admittance method. In addition, there is spatial variation of the Te values over the area analyzed. Our estimated Te values are low (1-6 km) along the Chagos-Laccadives ridge, implying its proximity to a spreading ridge at the time of creation. The Te values along the Mascarene Plateau show spatial variation with a seafloor age from north (Te, ca. 4 km) to south (Te, ca. 20 km). These findings substantiate earlier data and suggest that Réunion was created due to intraplate volcanism.
A new assessment of the elastic thickness (Te) structure of the Indian shield, and its implications
Authors: Deshraj Trivedi  , Yudhvir Singh  , Tanmay K. Maji  , Suresh Ch. Kandpal  , Rajesh R. Nair
Published: June 2021

The elastic thickness (Te) of continents is a matter of much debate. Recent studies have shown that a number of factors control the continental Te, including age, heat flow, and lithospheric thickness. Here, we estimate the Te structure of the whole Indian shield using an improved isotropic fan wavelet land ocean deconvolution methodology, and we compare these results with the global published Te estimates in the Archean, Proterozoic and younger geological provinces. Our study reveals low (0-45 km/0-35 km), intermediate (45-70 km) and high (70-100 km) Te values in the Archean/Quaternary, the Proterozoic, and the Tertiary provinces, respectively, of the Indian shield. This is in contrast with global estimates of Te in similar geological provinces. In the absence of any correlation of Te with any controlling parameters, we propose that the mantle properties, rather than the tectonic history, are responsible for influences on the Te values within the Indian shield. The global positioning system horizontal velocity vectors yielded a locking depth of ca. 20 ±4 km, and the aseismic creep beyond correlates well with the high strength of ca. 70 km to 100 km in the central Himalayan foreland.
Misure dei raggi X solari per mezzo dei satelliti
Authors: G. RIGHINI
Published: June 2021

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I pionieri italiaNi della geofisiCa
Authors: P. CALOI
Published: June 2021

Vengono rapidamente passati in rassenga, seguendo
l'ordine cronologico, gli studiosi di geofisica — intesa in senso lato — clie,
a partire dalla seconda meta del Settecento, ebbero ad interessarsi in Italia
di elettricita atmosferica, magnetismo terrestre, idrografla, oceanografia fisica,
sismologia e vulcanologia, con intenti pionieristici. Sono ricordati i principali
risultati raggiunti da una trentina di ricercatori fra i quali spiccano, per la
vastita del lavoro compiuto e per la novita dei risultati, Leopoldo Nobili e Macedonio
Melloni. Ma, ciascuno nei suo campo, scoperte di rilievo fecero pure
G. B. Beccaria, Luigi Palmieri, Carlo Matteucci, Timoteo Bertelli, Luigi De
Marcbi, Carlo Somigliana, Emilio Oddone, Alfonso Sella e Domenico Pacini.
Alcuni vantano priorita di rilievo: scoperta della doppia oscillazione diurna
del barometro (Chiminello, 1780); unicita sorgiva delle varie radiazioni dello
spettro (M. Melloni); sismografo elettromagnetico a registrazione continua
(Palmieri, 1855); microsismi (Bertelli, 1872); il paleomagnetismo (Oddone e
Sella, 1891); la radiazione cosmica (Pacini, 1910); . ..
L' abbassamento dell' EGO-isopieziche
Authors: A. BELLUIGI
Published: June 2021

Nel '57 demmo una teoria tridimensionale del fenomeno
elettrogeosmotieo « EGO stazionario », in terreno omogeneo, saturo d'acqua.
Successivamente sviluppammo teorie transitorie mono e bidimensionali:
« EGO trans ».
Abbiamo ripreso, con qualclie variante, qui, tale teoria tridimensionale,
ai fini di calcolare e conseguire poi, nel miglior modo possibile, l'abbassamento
delle superfici di depressione delle falde idriclie drenate elettrosmoticamente,
con poinpaggio catodico, (in genere dell'acqua tellurica).
Tale slivellamento idrico, rispetto al normale del terreno umido, e ricliiesto
in piu casi: nei terreni di fondazione per posa, su giaciture il piu
possibilmente anidre, negli imbasamenti soggetti a yicende idrogeologiche,
(e quindi comportanti dissesti statici delle s t r u t t u r e sovrincombenti, specie
in opere vetuste, monumentali), in opere varie, silos interrati, camminamenti,
scavi, tunnels, carreggiate, trincee, (senza pericoli di distaCchi, smottamenti
di flancate, fluitazioni di limi).
E ben noto che con i normali pompaggi in pozzi e fori di sonda, (Wellpoint
compresi), specie in argilloidi o in terreni pulvurulenti a finissima granulometria,
dispendiosi oltre misura, non si ottengono clie parziali, incerti
risultati.
II t r a t t a m e n t o EGO interviene a questo punto, in maniera decisiva e
risolutiva.
Quali allora le modalita d'impiego di dispositivi elettrodici e relativi
condizionamenti elettrici a t t i a raggiungere le finalita d'abbassamento egoisojjiezico?
£ stato possibile poter dimostrare da p a r t e nostra, in questa Memoria,
clie le profondita d'elettroregressione delle tavole d'acqua nel sottosuolo,
sono funzioni, oltre che dei coefficienti di flltrazione idrica ed elettrica dei
mezzi impregnati d'acqua, della tensione elettrica applicata, di modalita
d'erogazione, oltre clie dei dispositivi polari, spaziature e consistenze elettrodicbe.
UK 2009-2010 repeat station report
Authors: Thomas J.G. Shanahan  , Anthony P. Swan  , Susan Macmillan
Published: June 2021

The British Geological Survey is responsible for conducting the UK geomagnetic repeat station programme. Measurements made at the UK repeat station sites are used in conjunction with the three UK magnetic observatories: Hartland, Eskdalemuir and Lerwick, to produce a regional model of the local field each year. The UK network of repeat stations comprises 41 stations which are occupied at approximately 3-4 year intervals. Practices for conducting repeat station measurements continue to evolve as advances are made in survey instrumentation and as the usage of the data continues to change. Here, a summary of the 2009 and 2010 UK repeat station surveys is presented, highlighting the measurement process and techniques, density of network, reduction process and recent results.
Rilievo magnetometrico del giacimento di Fornovolasco
Authors: M. bernabini
Published: June 2021

Sono descritte le operazioni di campagna ed i metodiusati nell'interpretazione di un rilievo magnetometrico eseguito nella zonadel giacimento di pirite e magnetite di Fornovolasco (Lucca), sito sulle pendicidella Pania Secca (Alpi Apuane). Mediante le determinazioni di AH,AZ e AD è stato possibile ricavare in ogni stazione il vettore anomalo totale.L'interpretazione è stata basata sull'uso di modelli costituiti da elettrocalamiteprismatiche. I risultati dell'interpretazione sono discussi sulla basedelle conoscenze geominerarie sul giacimento.
Evidence of persistent seismo-volcanic activity at Marsili seamount
Authors: Antonino D'Alessandro  , Giorgio Mangano  , Giuseppe D'Anna
Published: June 2021

The Marsili submarine volcano is the largest European volcano, and it can be considered as the key to our understanding of the dynamics of the spreading and back-arc lithosphere formation in the Tyrrhenian sector [Marani et al. 2004, and references therein]. Despite its size, it is very difficult to monitor due to its geographical position [D'Alessandro et al. 2011], and it still remains little known. In 2006, the Centro Nazionale Terremoti (National Earthquake Centre) of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) deployed a broadband ocean-bottom seismometer with hydrophone (OBS/H) [Mangano et al. 2011] on the flat top of Marsili volcano, at a depth of ca. 790 m. In only nine days, the instrument recorded ca. 800 seismo-volcanic events [D'Alessandro et al. 2009]. This revealed the intense seismo-volcanic activity of Marsili volcano for the first time. […]

 
Comment on the report "Operational Earthquake Forecasting" by the International Commission on Earthquake Forecasting for Civil Protection
Authors: Stuart Crampin
Published: June 2021

The recently published report Operational Earthquake Forecasting: State of Knowledge and Guidelines for Utilization by the International Commission on Earthquake Forecasting for Civil Protection (ICEF) presupposes that there is no method for the short-term prediction of large earthquakes that has been demonstrated to be both reliable and skillful. This is no longer correct. Earthquakes can be deterministically stress-forecast by using shear-wave splitting to monitor stress-accumulation in the rock mass surrounding the earthquake source. This new understanding of fluid-rock deformation means that the recommendations of the ICEF Report are no longer appropriate. This comment reviews this new understanding and suggests that the way forward for operational earthquake forecasting in Italy is to install one or more controlled-source three-borehole Stress-Monitoring Sites and use shear-wave splitting to monitor stress-accumulation and stress-forecast all damaging (M ≥ 5) earthquakes in Italy.
The use of non-invasive field techniques in the study of small topographically closed lakes: two case studies in Sicily (Italy)
Authors: Paolo Madonia  , Marianna Cangemi  , Francesco Paolo Di Trapani
Published: June 2021

Small endhoreic (topografically closed) lakes represent a little percentage of continental waters but, in arid or sub-arid regions, they develop special ecosystems potentially prone to ecological involution due to climatic changes. The mandatory use of light, non-invasive field techniques is often required, especially in protected areas. In the present work the use of non-invasive techniques like GPS−based bathymetric and photographic surveys have been applied to the study of two lakes, Specchio di Venere and Sfondato (Sicily, southern Italy), both natural reserves. The comparison between historical surveys and modern GPS−based bathymetries highlighted the difficulty of using the former for the reconstruction of climatic-induced variations due to the low number of measurements (spatial aliasing). In particular, at the intracaldera Lake Specchio di Venere, a high resolution survey gave new insights into a peculiar geo-ecosystem whose evolution is driven by both volcanic phenomena and biomineralization processes. On the contrary, the morphology of Lake Sfondato floor is much more simple and driven only by the superimposition of a detrital sedimentation on the initial collapse that generated the lake. The comparison betweem direct measurements and estimated changes of lake level, carried out between February 2008 and October 2009 variations, allowed us to test different hypotheses of hydrological balances, leading to opposite conclusions with respect to previous studies and remarking the fundamental importance of direct measurements in the validation of theoretical hydrological models.
Buried active faults in the Zafferana Etnea territory (south-eastern flank of Mt. Etna): geometry and kinematics by earthquake relocation and focal mechanisms
Authors: Salvatore Alparone  , Salvatore D'Amico  , Salvatore Gambino  , Vincenza Maiolino
Published: June 2021

We relocated seismicity that occurred from 2000 to 2005 inside a sector of Mt. Etna, comprising the town of Zafferana Etnea, using the double-difference technique. This approach revealed some spatial clusters of events at depths of 3.0 km to 5.5 km b.s.l., which suggested NE-SW-oriented and NNW-SSE-oriented active structures located west and north-west with respect to Zafferana Etnea. We also calculated 64 fault plane solutions, and azimuth and dip distributions of maximum compression P axes. The data include eight events with magnitudes between 3.1 and 3.7 that caused damage to Zafferana Etnea. This approach has allowed the definition of the geometry of structures that show no surface evidence, but are potentially hazardous for this territory. These faults might be linked to the regional tectonics, although they were activated by stress changes related to a general pressurizing of the Mt. Etna magma system between 2000 and 2005.
Full three-dimensional relocation and tomographic inversion of the 1977-2008 earthquakes in north-eastern Italy: a feasibility study
Authors: Aldo Vesnaver  , Luca Urpi
Published: June 2021

In a regional seismological network, the estimation of the epicenter is usually robust, especially for events inside or close to the network boundaries. In contrast, the hypocentral depth is very sensitive to the assumed velocity field. In this study, we compare the hypocenter estimates obtained by a classical algorithm in a simple one-dimensional (1D) model with a recently developed full 3D model that is based on shrinking grids. This study is preliminary, as the 3D Earth model is based on limited data from the literature; however, it demonstrates that different patterns show up when a more representative geological model is adopted. This encourages further studies, based on fully integrated 3D models from active surface seismic, well data and other geophysical measurements. Such an integrated approach has been successfully adopted by the oil and gas industries for decades, which has increased the exploration success rate and the production of hydrocarbon reservoirs.
GRAFICO PER IL CALCOLO DEL PUNTO DI RUGIADA MEDIANTE LO PSICROMETRO
Authors: M. TENANI
Published: June 2021

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PRIMI RISULTATI SULLA LOCALIZZAZIONE DELLE PERTURBAZIONI ATMOSFERICHE DALL'ESAME DELLE ONDE MICROBARICHE
Authors: FERRUCCIO MOSETTI
Published: June 2021

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SU ALCUNE PROPRIETÀ NOTEVOLI DEL ROTORE DEL VENTO DI GRADIENTE
Authors: FELICE DI BENEDETTO
Published: June 2021

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IL TERREMOTO SARDO DEL 13 NOVEMBRE 1948
Authors: FRANCESCO PERONACI
Published: June 2021

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VARIAZIONE DIURNA DELLA GRAVITÀ IN EUROPA. Nota 3° : Soluzione pratica
Authors: CARLO MORELI
Published: June 2021

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Commissione sismologica europea - Riunione di Utrecht (8-12 Aprile 1958)
Authors: P. CALOI
Published: June 2021

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Die Tiefen der Erdbebenherde in Deutschland auf Grund makroseismischer Berechnungen
Authors: W. SPONHEUER
Published: June 2021

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Le sesse del lago di Como - Parte I
Authors: P. CALOI  , M. C. SPADEA
Published: June 2021

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Un criterio di resistività pratico di trasformazione fra diagrammi apparente ottenuti con differenti dispositivi
Authors: R. CASSINIS
Published: June 2021

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Sul significato della presenza di metano nelle manifestazioni esalative e idrotermali
Authors: ALFONSO DI NOI
Published: June 2021

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The May 2012 Pianura Padana Emiliana seismic sequence: INGV strong-motion data website
Authors: Marco Massa  , Sara Lovati  , Rodolfo Puglia  , Gabriele Ameri  , Dario Sudati  , Emiliano Russo  , Gianlorenzo Franceschina  , Lucia Luzi  , Francesca Pacor  , Paolo Augliera
Published: June 2021

On May 20th 2012, at 02:03:52 UTC, a ML 5.9 (Mw 6.0) earthquake struck northern Italy (http://cnt.rm.ingv.it/). The epicentre was localized at 44.89˚ N and 11.23˚ E, in an area among the cities of Ferrara, Modena and Mantova. The event occurred at a depth of about 6.3 km, and was characterized by a reverse focal mechanism (http://cnt.rm.ingv.it/tdmt.html/). From May 20th, thousand of earthquakes, the strongest of which with a ML 5.8 (May 29th, 07:00:03 UTC), occurred in the same area (http://iside.rm.ingv.it/).This note presents a new web site, www.mi.ingv.it/ISMD/ismd.html/ (Figure 1) that includes about 2000 three-component strong-motion recordings of the events with 4.0 ≤ ML ≤ 5.9 occurred in the central part of the Pianura Padana Emiliana (northern Italy) from May 20th to June 12th. The data come from all INGV strong-motion stations installed in northern Italy (i.e. strong-motion stations of the National Seismic Network, RSN [Amato and Mele 2008]; Strong-Motion Network of Northern Italy, RAIS, http://rais.mi.ingv.it/ [Augliera et al. 2011]) and selected with a minimum latitude of 43.5˚ N. The earthquake locations reported in the web site come from the National Earthquake Centre of INGV (http://cnt.rm.ingv.it/).
DEDUZIONE DELLE CONCENTRAZIONI DI URANIO E TORIO NELLE SOSTANZE RADIOATTIVE CON IL METODO FOTOGRAFICO
Authors: G. IMBÒ  , L. CASERTANO
Published: June 2021

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SUL VENTO PREVALENTE A PAVIA
Authors: G. ALIVERTI  , E. AVICO
Published: June 2021

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SULLE OSCILLAZIONI LIBERE DEL LAGO DI ALBANO
Authors: P. CALOI  , M. GIORGI
Published: June 2021

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SULLA FISSIONE SPONTANEA DELL'URANIO TERRESTRE
Authors: C. FESTA  , M. SANTANGELO
Published: June 2021

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CONVENGNI E CONGRESSI
Authors: AAVV AAVV
Published: June 2021

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On Lg as read in North American records
Authors: I. Lehman
Published: June 2021

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Elementi per una teoria dei giacimenti di vapore naturale
Authors: C. Contini
Published: June 2021

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Il terremoto di Jenice del 18.03.1953 e le caratteristiche sismiche dell'Anatolia
Authors: F. Peronaci
Published: June 2021

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STUDIO DEL TERREMOTO DELLE ISOLE LIPARI DEL 13 APRILE 1938
Authors: P. CALOI
Published: June 2021

È la prima parte di uno studio riguardante un terremoto ad ipocentroprofondo verificatosi nel Tirreno Meridionale. Dopo' una brevediscussione sui terremoti ad origine profonda in rapporto con la geologiasuperficiale e profonda, viene fatta una esposizione critica deimetodi che sono stati qui usati per la determinazione delle coordinatespazio-temporali. Viene confermata la profondità di 300 km, eccezionaleper il Mediterraneo. L'epicentro risulta situato sull'allineamentodella fascia vulcanica attiva, che va dal Vesuvio all'Etna, in una regionesede di una cospicua anomalia isostatica positiva.
Una nota sul vento isallobarico
Authors: F. Di Benedetto
Published: June 2021

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Variazioni stagionali e non stagionali della densità elettronica ionosferica
Authors: F. Mariani
Published: June 2021

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POLARIZZAZIONE DELLA S DEI SISMOGRAMMI
Authors: R. Stoneley
Published: June 2021

ISei terremoti registrati a distanze non troppo grandi si è osservato che la faseS appare prima come una SU. seguita 10 o 14 sec più lardi da una Sì'. La presentenota si propone di decidere se la doppia rifrazione è in grado di spiegarequesto fenomeno.Un modello semplice sarebbe costituito da un materiale « isotropo trasversalmente», simmetrico attorno alla direzione radiale. Si possiedono le formule per levelocità delle onde SII e SI : esse dipendono dall'angolo che il raggio forma conla normale.È improbabile che la terra possa essere anisotropa in maniera tanto rilevantequanto il berillio, che è isotropo trasversalmente; di conseguenza questo materiale,del quale si conoscono le sei costanti elastiche, è stato assunto come un esempioestremo e le velocità delle SII e delle SV per differenti angoli di incidenza sonostate « aggiustate » in modo da ottenere le velocità delle onde di distorsione nelgranito. È cos) possibile calcolare la differenza tra i tempi occorrenti <die onde perpassare da un punto della superficie terrestre a un altro punto della superficiestessa, a seconda che l'onda S nello strato superficiale è del tipo SII o SV.Si trova che, anche in questo caso estremo, uno strato di roccia anisotropospesso circa 30 km darà origine ad una differenza di tempo di solo l]/> secondi.Cioè se la terra fosse cos'i fortemente anisotropa quanto il berillio (il che è improbabile)bisognerebbe che lo strato a orientazione preferenziale si estendesse finoa una profondità di circa 300 km. Ciò è piuttosto improbabile, dimodoché nonconviene attribuire un gran credito alle spiegazioni fondate sulla doppia rifrazione.
RISULTATI DI UN ANNO DI MISURE ESEGUITE A P A V I A , A CIELO SERENO, CON IL DOSIMETRO PER L'ULTRAVIOLETTO
Authors: g. Aliverti  , G. PANNOCCHIA
Published: June 2021

Si pubblicano i risultati di un anno di misure eseguite a Pavia,a cielo sereno, con il dosimetro per l'ultravioletto e si mette in rilievocome le nostre misure, d'accordo con quelle analoghe di altri sperimentatori,denuncino un andamento annuo della radiazione UV chenon si accorda con l'andamento annuo del contenuto in ozono osservatodalle stazioni che seguono regolarmente tale contenuto. Si mettonopure in evidenza alcune condizioni sperimentali che potrebberointervenire nel determinare il disaccordo.
UNO STUDIO SUL TERREMOTO DEL GRAN SASSO D' ITALIA DEL 5 SETTEMBRE 1950
Authors: d. DI FILIPPO  , L. Marcelli
Published: June 2021

Nel presente lavoro si espongono i risultati della prima parte diuno studio sul terremoto del Gran Sasso d'Italia avvenuto il 5 settembre10.50. Si riportano le notizie macrosismiche, e viene tracciatala rete delle isosiste. Calcolata la magnitudo, l'energia, l'epicentro incoordinate ortogonali e geografiche, le velocità delle Pg, Pn, Sg, Sncon le relative dromocrone, il tempo origine,
IL TERREMOTO JONICO DEL 22 APRILE 1948
Authors: p. Valle
Published: June 2021

Allo scopo di contribuire alla localizzazione dei centri sismiciche interessano l'Italia e per essere in jtossesso dei dati fondamentaliper una successiva ricerca, sono state calcolate le coordinate epicentralie il tempo origine del terremoto Jonico del 22 aprile 1948.
Numeri caratteristici dei flocculi d'idrogeno e di calcio e dei filamenti d'idrogeno per l'anno 1957
Authors: G. Godoli
Published: June 2021

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RISULTATI DI SONDAGGI E DI RICERCHE GEOMINERARIE NEI «CAMPI ELEGREI» PER VAPORE, ACQUE TERMALI E «FORZE ENDOGENE» IN GENERALE
Authors: F. Penta  , b. conforto
Published: June 2021

Dal 1939 al 1943 furono eseguiti nei Campi Flegrei e precisamentenelle località « Le Mofete », « Monte Nuovo » e « Agnano »,alcuni sondaggi profondi da qualche decina di metri fino a diversecentinaia di metri per determinare le principali caratteristiche fisiche,chimiche e pelrografiche del sottosuolo in zone presentanti notevolimanifestazioni fumaroliche o prossime ad aree ricche di esalazioni.Rimandiamo ad altre note (*) per la descrizione dettagliata deifori più profondi, dei terreni incontrati, delle manifestazioni in esseriscontrate e per qualche conclusione generale. Come già per le ricerchenell'isola d'Ischia (2), esponiamo qui di seguito brevi notizierelative ai fori trivellati che furono tenuti in osservazione per qualchetempo I fino a quattro anni qualcuno) nel tentativo di inquadrarela fenomenologia, oggetto di studio, agli effetti ultimi della utilizzazionedelle acque termali per forza motrice e della ricerca di vaporeacqueo profondo (3).Tali notizie permetteranno di valutare meglio le caratteristicheriscontrate e raccolte nelle tabelle accluse.
EFFETTI DELL'ATTRITO INTERNO SULLA VELOCITA' DELLE ONDE SISMICHE SUPERFICIALI A BREVISSIMO PERIODO (*)
Authors: P. Caloi
Published: June 2021

Tra i vari effetti dell' attrito interno sulla propagazione delle ondesuperficiali di Rayleigh, va notato quello sulla velocità: tale grandezzaè fortemente influenzata dall'azione dell'attrito interno, nel senso chela velocità di propagazione delle onde di Rayleigh, in un mezzo cheammette attrito interno, da un valore infinito per periodi nulli, tenderapidamente al valore che le compete in un mezzo puramente elastico.D'altronde, poiché anche l'azione assorbente del mezzo tende all'infinitocol tendere del periodo a zero, se ne conclude che l'effettodell'attrito interno sulla velocità di propagazione può essere constatatosolo per piccole distanze.Recentemente, una conferma sperimentale di questo effetto è stataottenuta dai giapponesi Ikegami e Kishinouye.
TEMPI DI TRAGITTO DELLE ONDE P* E SPESSORE DELLO STRATO DEL GRANITO NELL'ITALIA CENTRALE
Authors: D. DI FILIPPO  , L. Marcelli
Published: June 2021

Proseguendo lo studio del terremoto del Gran Sasso d'Italia del5 settembre 1950 si rilevano alcune caratteristiche sismiche dell'Italiacentrale.Si determina la profondità ipocentrale con il metodo dell'angolodi emergenza. Indi si costruisce la dromocrona delle P* e si calcolalo spessore dello strato del granito relativamente alla zona.
LA «MAGNITUDO» DEI TERREMOTI E LA SUA DETERMINAZIONE NELLA STAZIONE SISMICA DI ROMA
Authors: D. DI FILIPPO  , L. MARCELLI
Published: June 2021

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CONTRIBUTO ALLO STUDIO DELLA COSIDETTA «FASE PRINCIPALE» DI UN SISMOGRAMMA
Authors: S. MENIS  , C. MORELLI
Published: June 2021

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COEFFICIENTE DI DIFFUSIONE DI ELETTRONI IN UN GAS
Authors: DONATO PALUMBO
Published: June 2021

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L'ONDA «G» DI GUTENBERG NEL TERREMOTO DELLE AZZORRE DEL 25 NOVEMBRE 1941
Authors: DOMENICO DI FILIPPO
Published: June 2021

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STUDIO COMPARATIVO DEI MICROSISMI REGISTRATI A ROMA ED A TRIESTE
Authors: CARLO MORELI
Published: June 2021

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SULLA RACCOLTA DELLE SOSTANZE CHE ESALANO DURANTE LA RIFUSIONE DELLE ROCCE ERUTTIVE
Authors: G. PONTE
Published: June 2021

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NUOVI CRITERI PER LA SISTEMAZIONE MAGNETICA
Authors: CARLO MORELI
Published: June 2021

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SULLA RAPPRESENTAZIONE IN SUPERFICIE DELLA NATURA DINAMICA DI UNA SCOSSA CON IPOCENTRO PROFONDO
Authors: DOMENICO DI FILIPPO
Published: June 2021

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PROBLEMI MATEMATICI NELLA GEOFISICA
Authors: ERWIN HARDTWIG
Published: June 2021

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MISURE GRAVI METRICHE NELLE GROTTE DI CASTELLANA
Authors: G. BOAGA  , G. TRIBALDO  , G. ZACCARA
Published: June 2021

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SULLA VELOCITA' DI PROPAGAZIONE DELLE ONDE SISMICHE SU BREVI PERCORSI
Authors: G. ALIVERTI  , L. SOLAINI
Published: June 2021

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SULLA ABBONDANZA ORIGINARIA DEL K40
Authors: CAMILLA FESTA
Published: June 2021

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LE MAREE ALL'ISOLA DI S. ANDREA NELL'ADRIATICO CENTRALE
Authors: SILVIO POLLI
Published: June 2021

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FEDERATION SEISMOLOGIQUE EUROPEENNE (F.S.E.)
Authors: AAVV AAVV
Published: June 2021

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