1,720,977 research outputs found
Space geodetic activities, from the early days to present, with focus on the northeastern Adriatic
No full textIt has become of greatest importance to monitor
and understand how the dynamics of the System Earth
works. Geodesy has gone far beyond the provision of a
static knowledge of the Earth’s geometric and physical
parameters and with the development of high-accuracy
satellite and space techniques and increased measurement
capability, this discipline is now providing observations of
changes in the Earth’s shape, gravity field and rotation
which are essential for Earth system science. In a short
historical excursus of the main space geodetic techniques,
we review achievements in the determination and study of
Earth’s crustal deformation and sea-level change/variations.
Focus is given to geodetic research activities developed
in northeastern Italy
Earthquake catalogs for: Improving detection of micro-earthquakes in the Val d'Agri region (Southern Italy) using Deep Learning algorithms
No full textThis repository contains two earthquake catalogs (dubbed PRN and QS) obtained from the application of two deep-learning-based detection workflows to continuous seismic data recorded in the Val d’Agri region (Southern Italy). These catalogs have been generated using the PhaseNet neural network for seismic phase picking (Zhu & Beroza, 2019). The workflows used to generate the catalogs are described in detail in: Caredda et al. (2025). These datasets offer a more comprehensive representation of local seismicity compared to manually generated, STA/LTA-based catalogs (available in the open periodic monitoring reports accessible at: https://cms.ingv.it/sperimentazioni/val-d-agri [last accessed on 18/09/2025]).
The datasets include event origin times, locations, magnitudes, location uncertainties, and phase arrival times with corresponding PhaseNet “pick probabilities” (for the PRN catalog), providing an enriched representation of local seismicity compared to conventional STA/LTA-based catalogs.
These catalogs can serve as valuable resources for further research on seismicity, induced processes, Earth structure, and seismic hazard assessment in the Val d’Agri region.
References:
Caredda, E., M.P. Isken, S. Cesca, M. Errico, G. Zerbinato, and A. Morelli (2025) Improving detection of micro-earthquakes in the Val d’Agri region (Southern Italy) using deep learning algorithms, Seismica (in press).
Zhu, W., and Beroza, G. C. (2018). PhaseNet: A Deep-Neural-Network-Based Seismic Arrival Time Picking Method. Geophysical Journal International, 216(1), 261–273. https://doi.org/10.1093/gji/ggy42
Monitoring and understanding crustal deformation by means of GPS and InSAR data
Full text linkMonitoring deformation of the Earth’s crust by using data acquired by both the GNSS and SAR techniques allows
describing crustal movements with high spatial and temporal resolution. This is a key contribution for achieving a
deeper and better insight of geodynamic processes. Combination of the two techniques provides a very powerful
means, however, before combing the different data sets it is important to properly understand their respective
contribution. For this purpose, strictly simultaneous and long time series would be necessary. This is not, in
general, a common case due to the relatively long SAR satellites revisit time. A positive exception is represented
by the data set of COSMO SKYMed (CSK) images made available for this study by the Italian Space Agency
(ASI). The flyover area encompass the city of Bologna and the smaller nearby town of Medicina where permanent
GPS stations are operational.
At the times of the CSK flyovers, we compared the GPS and SAR Up and East coordinates of a few stations as
well as differential tropospheric delays derived by both techniques. The GPS time series were carefully screened
and corrected for the presence of discontinuities by adopting a dedicated statistical procedure. The comparisons
of both the estimated deformation and the tropospheric delays are encouraging and highlight the need for having
available a more evenly sampled SAR data set
Long-period sea-level variations in the Mediterranean
No full textSince the beginning of its long-lasting lifetime, the Wegener initiative has devoted careful consideration to studying sea-level variations/changes across the Mediterranean Sea. Our study focuses on several long-period sea-level time series (from end of 1800 to 2012) acquired in the Mediterranean by tide gauge stations. In general, the analysis and interpretation of these data sets can provide an important contribution to research on climate change and its impacts. We have analyzed the centennial sea-level time series of six fairly well documented tide gauges. They are: Marseille, in France, Alicante in Spain, Genoa, Trieste, Venice and Marina di Ravenna (formerly Porto Corsini), in Italy. The data of the Italian stations of Marina di Ravenna and Venice clearly indicate that land subsidence is responsible for most of the observed rate of relative sea level rise. It is well known that, in the two areas, subsidence is caused by both natural processes and human activities. For these two stations, using levelling data of benchmarks at, and/or close to, the tide gauges, and for the recent years, also GPS and InSAR height time series, modelling of the long-period non-linear behavior of subsidence was successfully accomplished. After removing the land vertical motions, the estimate of the linear long-period sea-level rise at all six stations yielded remarkably consistent values, between +1,2 and +1,3 mm/yr, with associated errors ranging from ±0,2 to ±0,3 mm/yr (95% confidence interval), which also account for the statistical autocorrelation of the time series. These trends in the Mediterranean area are lower than the global mean rate of 1,7±0,2 mm/yr (1901-2010) presented by the IPCC in its 5th Assessment Report; however, they are in full agreement with a global mean sea-level rise estimate, over the period 1901-1990, recently published by Hay et al. (2015, doi:10.1038/nature14093) and obtained using probabilistic techniques that combine sea-level records with physics-based and model-derived geometries of the contributing processes. An EOF analysis (Empirical Orthogonal Functions) has also been carried out on the six sea-level time series to identify the dominant modes of variability
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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