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  • 04.06. Seismology  (12)
  • 04.04. Geology
  • Antarctic bacterioplankton
  • Seismological Society of America  (9)
  • Wiley  (5)
  • Nature Publishing Group
  • American Institute of Physics (AIP)
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  • 1
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    The micro‐seismicity of Co. Donegal (Ireland): Defining baseline seismicity in a region of slow lithospheric deformation (2024)
    Wiley
    Details
    Publikationsdatum: 2024-02-07
    Beschreibung: A catalogue of precisely located micro-seismicity is fundamental for investigating seismicity and rock physical properties in active tectonic and volcanic regions and for the definition of a ‘baseline’ seismicity, required for a safe future exploitation of georesource areas. In this study, we produce the first manually revised catalogue of micro-seismicity for Co. Donegal region (Ireland), an area of about 50K M2 of on-going deformation, aimed at localizing natural micro-seismic events occurred between 2012 and 2015. We develop a stochastic method based on a Markov chain Monte Carlo (McMC) sampling approach to compute earthquake hypocentral location parameters. Our results indicates that micro-seismicity is present with magnitudes lower than 2 (the highest magnitude is 2.8).The recorded seismicity is almost clustered along previously mapped NE-SW trending, steeply dipping faults and confined within the upper crust (focal depth less than 10 km). We also recorded anthropogenic seismicity mostly related to quarries' activity in the study area.
    Beschreibung: Published
    Beschreibung: 62-76
    Beschreibung: OST1 Alla ricerca dei Motori Geodinamici
    Beschreibung: JCR Journal
    Schlagwort(e): 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 2
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    The Influence of Cumulative Intensity on Macroseismic Source Parameters: The Case of 2016–2017 and 1703 Seismic Sequences (Central Italy) (2024)
    Seismological Society of America
    Details
    Publikationsdatum: 2024-03-12
    Beschreibung: The macroseismic source parameters of earthquakes occurring within a sequence are strongly influenced by cumulative damage effects. When we deal with historical seismic sequences, in addition to the cumulative intensities, other intrinsic uncertainties due to the scarcity and indeterminacy of sources come into play. These issues imply that the parameterizations of the single earthquakes within a historical seismic sequence are not univocal and that all the uncertainties that are addressed when assessing macroseismic intensity should be carefully considered in the parameter estimation. In the light of these considerations, we performed some tests on the 2016–2017 and 1703 seismic sequences, which occurred in the same area in central Italy, to compute the macroseismic source parameters by means of two independent methods. Results show that the cumulative effects arising from multiple damaging earthquakes can cause biases in the intensity assessments, which affect the computed magnitude and epicentral locations. To reduce bias in macroseismic intensities due to cumulative damage, we illustrate a simple procedure, called cumulative intensity subtraction (CIS), which consists in discarding the localities strongly damaged by the early earthquakes of a sequence from the intensity distributions used for computing the macroseismic source parameters of the subsequent earthquakes. The outcomes show that, for the 2016 seismic sequence, the CIS approach provides locations in agreement with the instrumental epicenters and with the causative faults. For the 1703 sequence, the CIS approach along with explicit accounting for the indeterminacy in intensity assignments give a range of equally plausible solutions. The CIS represents an exploration of a simple strategy that stems from an attempt to give significance to macroseismic intensity in the presence of cumulative damage.
    Beschreibung: Published
    Beschreibung: 759–774
    Beschreibung: OST4 Descrizione in tempo reale del terremoto, del maremoto, loro predicibilità e impatto
    Beschreibung: JCR Journal
    Schlagwort(e): macroseismic intesity ; cumulative effects ; microseismic source parameters ; 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 3
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    Imaging Upper-Mantle Anisotropy with Transdimensional Bayesian Monte Carlo Sampling (2024)
    Seismological Society of America
    Details
    Publikationsdatum: 2024-04-09
    Beschreibung: Underdetermination is a condition affecting all problems in seismic imaging. It manifests mainly in the nonuniqueness of the models inferred from the data. This condition is exacerbated if simplifying hypotheses like isotropy are discarded in favor of more realistic anisotropic models that, although supported by seismological evidence, require more free parameters. Investigating the connections between underdetermination and anisotropy requires the implementation of solvers which explore the whole family of possibilities behind nonuniqueness and allow for more informed conclusions about the interpretation of the seismic models. Because these aspects cannot be investigated using traditional iterative linearized inversion schemes with regularization constraints that collapse the infinite possible models into a unique solution, we explore the application of transdimensional Bayesian Monte Carlo sampling to address the consequences of underdetermination in anisotropic seismic imaging. We show how teleseismic waves of P and S phases can constrain upper‐mantle anisotropy and the amount of additional information these data provide in terms of uncertainty and trade‐offs among multiple fields.
    Beschreibung: In press
    Beschreibung: OST1 Alla ricerca dei Motori Geodinamici
    Beschreibung: JCR Journal
    Schlagwort(e): 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 4
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    The Dependence on the Moho Depth of the b-Value of the Gutenberg–Richter Law (2023)
    Seismological Society of America
    Details
    Publikationsdatum: 2023-03-31
    Beschreibung: We investigate the dependence of the Gutenberg–Richter b parameter on the crustal thickness quantified by the Moho depth, for nine different regional catalogs. We find that, for all the catalogs considered in our study, the b‐value is larger in areas presenting a thicker crust. This result appears in apparent contradiction with previous findings of a b decreasing with the focal depth. However, both the results are consistent with acoustic emission experiments, indicating a b‐value inversely proportion to the applied differential stress. Our results can be indeed interpreted as the signature of a larger stress concentration in areas presenting a thinner crust. This is compatible with the scenario where postseismic deformation plays a central role in stress concentration and in aftershock triggering.
    Beschreibung: Published
    Beschreibung: 1921–1934
    Beschreibung: 6T. Studi di pericolosità sismica e da maremoto
    Beschreibung: JCR Journal
    Schlagwort(e): b-value ; 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 5
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    Comment on “High-Definition Mapping of the Gutenberg–Richter b-Value and Its Relevance: A Case Study in Italy” by M. Taroni, J. Zhuang, and W. Marzocchi (2023)
    Seismological Society of America
    In:  Taroni, M., J. Zhuang, and W. Marzocchi (2021). High-definition mapping of the Gutenberg–Richter b-value and its relevance: A case study in Italy, Seismol. Res. Lett. 92, 3778–3784, doi: 10.1785/0220210017.
    Details
    Publikationsdatum: 2023-02-21
    Beschreibung: Taroni et al. (2021) published a statistical framework to reliably estimate the b-value and its uncertainties, with the goal being the interpretation in a seismotectonic context and improving earthquake forecasting capabilities. In this comment, we show that the results presented for the Italian region and the conclusions drawn by the authors, are heavily biased due to quarry-blast events in the Italian earthquake catalog used in the analysis. Without removing this anthropogenic component in the data, a meaningful analysis of the earthquake- size distribution for natural seismicity is, in our opinion, not possible. This comment highlights the need for basic data quality analysis before sophisticated statistical tools are applied to a dataset.
    Beschreibung: European Union’s Horizon 2020 research and innovation program under Grant Agreement Number 821115 Pianeta Dinamico-Working Earth INGV-MUR project.
    Beschreibung: Published
    Beschreibung: 1089-1094
    Beschreibung: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica
    Beschreibung: JCR Journal
    Schlagwort(e): 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 6
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    The Community Stress-Drop Validation Study—Part I: Source, Propagation, and Site Decomposition of Fourier Spectra (2023)
    Seismological Society of America
    Details
    Publikationsdatum: 2023-10-03
    Beschreibung: In part 1, we run multiple GIT decomposition for different choices of model assumptions, namely three different window duration for Fourier calculation, two different parametrization of the attenuation, two different site constraints. We also considered different source models (Brune, Boatwright, Brune with kappa_source) and different approaches to estimate uncertainties of source parameters (i.e., considering the covariance matrix, Monte Carlo sampling of the residual distribution, model selection with threshold based on F-test).
    Beschreibung: As part of the community stress-drop validation study initiative, we apply a spectral decomposition approach to isolate the source spectra of 556 events occurred during the 2019 Ridgecrest sequence (Southern California). We perform multiple decompositions by introducing alternative choices for some processing and model assumptions, namely: three different S-wave window durations (i.e., 5 s, 20 s, and variable between 5 and 20 s); two attenuation models that account differently for depth dependencies; and two different site amplification constraints applied to restore uniqueness of the solution. Seismic moment and corner frequency are estimated for the Brune and Boatwright source models, and an extensive archive including source spectra, site amplifications, attenuation models, and tables with source parameters is disseminated as the main product of the present study. We also compare different approaches to measure the precision of the parameters expressed in terms of 95% confidence intervals (CIs). The CIs estimated from the asymptotic standard errors and from Monte Carlo resampling of the residual distribution show an almost one-to-one correspondence; the approach based on model selection by setting a threshold for misfit chosen with an F-ratio test is conservative compared to the approach based on the asymptotic standard errors. The uncertainty analysis is completed in the companion article in which the outcomes from this work are used to compare epistemic uncertainty with precision of the source parameters.
    Beschreibung: Published
    Beschreibung: 1980–1991
    Beschreibung: 3T. Fisica dei terremoti e Sorgente Sismica
    Beschreibung: JCR Journal
    Schlagwort(e): source parameters ; GIT ; uncertainties ; moment magnitude ; corner frequency ; 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 7
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    Evaluation of the Event Detection Level of the Cuban Seismic Network (2023)
    Seismological Society of America
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    Publikationsdatum: 2023-01-23
    Beschreibung: The detection level of a seismic network is a measure of its effective ability to record small earthquakes in a given area. It can vary in both space and time and depends on several factors such as meteorological conditions, anthropic noise, local soil conditions—all factors that affect the seismic noise level—as well as the quality and operating condition of the instruments. The ability to estimate the level of detection is of tremendous importance both in the design of a new network and in determining whether a given network can recognize seismicity consistently or needs to be improved in some of its parts. In this article, we determine the detection level of the Cuban seismic network using the empirically estimated seismic noise spectral level at each station site and some theoretical relationships to predict the signal amplitude of a seismic event at individual stations. The minimum local detectable magnitude thus depends on some network parameters such as the signal‐to‐noise ratio and the number of stations used in the calculation. We also demonstrate the effectiveness of our predictions by comparing the estimated detection level with those empirically determined from one year of data (i.e., the year 2020) of the Cuban seismic catalog. Our analysis shows, on the one hand, in which areas the current Cuban network should be improved, also depending on the regional pattern of faults, and, on the other hand, indicates the magnitude threshold that can be assumed homogeneously for the catalog of Cuban earthquakes in 2020. Because the adopted method can use current measurements of the seismic noise level (e.g., daily), the proposed analysis can also be configured for continuous monitoring of network state quality.
    Beschreibung: Published
    Beschreibung: 2048-2062
    Beschreibung: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica
    Beschreibung: 1IT. Reti di monitoraggio e sorveglianza
    Beschreibung: JCR Journal
    Schlagwort(e): seismic monitoring ; detection ; cuba ; seismic network ; Event Detection Level ; 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 8
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    Minimum 1D Vp and Vp/Vs Models and Hypocentral Determinations in the Central Mediterranean Area (2023)
    Seismological Society of America
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    Publikationsdatum: 2023-03-01
    Beschreibung: Minimum 1D velocity models and station corrections have been computed for the central Mediterranean area using two main data sets. The first one consists of accurate first arrival‐time readings from 103 seismic events with magnitude (ML)≥3.5 recorded by the Italian National Seismic Network (RSN) and the AlpArray Seismic Network (AASN) in the period 2014–2021. Earthquakes were selected on the basis of their spatial distribution, epicentral distance to the nearest seismic station, and maximum distance traveled by Pn and Sn phases. This fine selection of high‐quality data combined with the spatial density of the AlpArray seismic stations was decisive in obtaining high resolution for upper mantle velocity, especially in the Alpine belt. To obtain a denser coverage of crustal rays, we extended the first data set with P and S arrivals of local earthquakes from Istituto Nazionale di Geofisica e Vulcanologia (INGV) bulletin data (2016–2018). A total of 75,807 seismic phases (47,183 P phases and 28,264 S phases) have been inverted to calculate best‐fit 1D velocity models, at regional and local scales. We then test the performance of the optimized velocity models by relocating the last four years of seismicity recorded by INGV (period 2017–2020). The computed velocity models are very effective for routine earthquake location, seismic monitoring, source parameter modeling, and future 3D seismic tomography.
    Beschreibung: Published
    Beschreibung: 2670--2685
    Beschreibung: 4T. Sismicità dell'Italia
    Beschreibung: JCR Journal
    Schlagwort(e): geophysics ; velocity models ; Italian seismicity ; central mediterranean area ; 04. Solid Earth ; 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 9
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    The impact of faulting complexity and type on earthquake rupture dynamics (2022)
    Nature Publishing Group
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    Publikationsdatum: 2022-10-31
    Beschreibung: The statistical properties of seismicity are known to be affected by several factors such as the rheological parameters of rocks. We analysed the earthquake double-couple as a function of the faulting type. Here we show that it impacts the moment tensors of earthquakes: thrust- faulting events are characterized by higher double-couple components with respect to strike- slip- and normal-faulting earthquakes. Our results are coherent with the stress dependence of the scaling exponent of the Gutenberg-Richter law, which is anticorrelated to the double- couple. We suggest that the structural and tectonic control of seismicity may have its origin in the complexity of the seismogenic source marked by the width of the cataclastic damage zone and by the slip of different fault planes during the same seismic event; the sharper and concentrated the slip as along faults, the higher the double-couple. This phenomenon may introduce bias in magnitude estimation, with possible impact on seismic forecasting.
    Beschreibung: Published
    Beschreibung: 258
    Beschreibung: 2T. Deformazione crostale attiva
    Beschreibung: JCR Journal
    Schlagwort(e): double couple ; damage zone ; different fault type ; seismicity ; tectonics ; fault type ; seismicity ; 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 10
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    Integrated on‐land‐offshore stratigraphy of the Campi Flegrei caldera: new insights into the volcano‐tectonic evolution in the last 15 kyr (2021)
    Wiley
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    Publikationsdatum: 2022-06-22
    Beschreibung: Silicic calderas are volcanic systems whose unrest evolution is more unpredictable than other volcano types because they often do not culminate in an eruption. Their complex structure strongly influences the post-collapse volcano-tectonic evolution, usually coupling volcanism and ground deformation. Among such volcanoes, the Campi Flegrei caldera (southern Italy) is one of the most studied. Significant long- and short-term ground deformations characterize this restless volcano. Several studies performed on the marinecontinental succession exposed in the central sector of the Campi Flegrei caldera provided a reconstruction of ground deformation during the last 15 kyr. However, considering that over one-third of the caldera is presently submerged beneath the Pozzuoli Gulf, a comprehensive stratigraphic on-land-offshore framework is still lacking. This study aims at reconstructing the offshore succession through analysis of high-resolution single and multichannel reflection seismic profiles and correlates the resulting seismic stratigraphic framework with the stratigraphy reconstructed on-land. Results provide new clues on the causative relations between the intra-caldera marine and volcaniclastic sedimentation and the alternating phases of marine transgressions and regressions originated by the interplay between ground deformation and sea-level rise. The volcano-tectonic reconstruction, provided in this work, connects the major caldera floor movements to the large Plinian eruptions of Pomici Principali (12 ka) and Agnano Monte Spina (4.55 ka), with the onset of the first post-caldera doming at ~10.5 ka. We emphasize that ground deformation is usually coupled with volcanic activity, which shows a self-similar pattern, regardless of its scale. Thus, characterizing the long-term deformation history becomes of particular interest and relevance for hazard assessment and definition of future unrest scenarios.
    Beschreibung: Published
    Beschreibung: 855-882
    Beschreibung: 1V. Storia eruttiva
    Beschreibung: JCR Journal
    Schlagwort(e): offshore stratigraphy ; seismic units ; La Starza succession ; volcanism, ; 04.08. Volcanology ; 04.04. Geology ; 04.07. Tectonophysics
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 11
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    Fine‐Scale Structure of the 2016–2017 Central Italy Seismic Sequence From Data Recorded at the Italian National Network (2020)
    Wiley
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    Publikationsdatum: 2020-05-25
    Beschreibung: We explore the three‐dimensional structure of the 2016–2017 Central Italy sequence using ~34,000 ML ≥ 1.5 earthquakes that occurred between August 2016 and January 2018. We applied cross‐correlation and double‐difference location methods to waveform and parametric data routinely produced at the Italian National Institute of Geophysics and Volcanology. The sequence activated an 80 km long system of normal faults and near‐horizontal detachment faults through the MW 6.0 Amatrice, the MW 5.9 Visso, and the MW 6.5 Norcia mainshocks and aftershocks. The system has an average strike of N155°E and dips 38°–55° southwestward and is segmented into 15–30 km long faults individually activated by the cascade of MW ≥ 5.0 shocks. The two main normal fault segments, Mt. Vettore‐Mt. Bove to the North and Mt. della Laga to the South, are separated by an NNE‐SSW‐trending lateral ramp of the Sibillini thrust, a regional structure inherited from the previous compressional tectonic phase putting into contact diverse lithologies with different seismicity patterns. Space‐time reconstruction of the fault system supports a composite rupture scenario previously proposed for the MW 6.5 Norcia earthquake, where the rupture possibly propagated also along an oblique portion of the Sibillini thrust. This dissected set of normal fault segments is bounded at 8–10 km depth by a continuous 2 km thick seismicity layer of extensional nature slightly dipping eastward and interpreted as a shear zone. All three mainshocks in the sequence nucleated along the high‐angle planes at significant distance from the shear zone, thus complicating the interpretation of the mechanisms driving strain partitioning between these structures.
    Beschreibung: Published
    Beschreibung: e2019JB018440
    Beschreibung: 3T. Sorgente sismica
    Beschreibung: JCR Journal
    Schlagwort(e): normal fault ; shear zone ; fault segmentation ; apennines ; 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 12
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    Active Extension in a Foreland Trapped Between Two Contractional Chains: The South Apulia Fault System (SAFS) (2020)
    Wiley
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    Publikationsdatum: 2020-07-08
    Beschreibung: The response of continental forelands to subduction and collision is a widely investigated topic in geodynamics. The deformation occurring within a foreland shared by two opposite‐verging chains, however, is uncommon and poorly understood. The Apulia Swell in the southern end of the Adria microplate (Africa‐Europe plate boundary, central Mediterranean Sea) represents one of these cases, as it is the common foreland of the SW verging Albanides‐Hellenides and the NE verging Southern Apennines merging into the SSE verging Calabrian Arc. We investigated the internal deformation of the Apulia Swell using multiscale geophysical data: multichannel seismic profiles recording up to 12‐s two‐way time (TWT) for a consistent image of the upper crust; high‐resolution multichannel seismic profiles, high‐resolution multibeam bathymetry, and CHIRP profiles acquired by R/V OGS Explora to constrain the Quaternary geological record. The results of our analyses characterize the geometry of the South Apulia Fault System (SAFS), a 100‐km‐long and 12‐km‐wide structure attesting an extensional (and possibly transtensional) response of the foreland to the two contractional fronts. The SAFS consists of two NW‐SE right‐stepping master faults and several secondary structures. The SAFS activity spans from the Early Pleistocene through the Holocene, as testified by the bathymetric and high‐resolution seismic data, with long‐term slip rates in the range of 0.2–0.4 mm/yr. Considering the position within an area with few or none other active faults in the surroundings, the dimension, and the activity rates, the SAFS can be a candidate causative fault of the 20 February 1743, M 6.7, earthquake.
    Beschreibung: Italian Ministry for Education, University, and Research (MIUR), Premiale 2014 D. M. 291 03/05/2016.
    Beschreibung: Published
    Beschreibung: e2020TC006116
    Beschreibung: 2T. Deformazione crostale attiva
    Beschreibung: 2TR. Ricostruzione e modellazione della struttura crostale
    Beschreibung: JCR Journal
    Schlagwort(e): active tectonics ; apulia ; south apulia fault system ; 1743 earthquake ; marine geology ; stable continental region ; ionian sea ; active faults ; subsurface geology ; seismic interpretation ; 04.04. Geology ; 04.07. Tectonophysics ; 04.02. Exploration geophysics
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 13
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    New coring study in Augusta Bay expands understanding of offshore tsunami deposits (Eastern Sicily, Italy) (2019)
    Wiley
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    Publikationsdatum: 2021-01-25
    Beschreibung: Tsunami deposits present an important archive for understanding tsunami histories and dynamics. Most research in this field has focused on onshore preserved remains, while the offshore deposits have received less attention. In 2009, during a coring campaign with theItalian Navy Magnaghi, four 1 m long gravity cores (MG cores) were sampled from the northern part of Augusta Bay, along a transect in 60 to 110 m water depth. These cores were taken in the same area where a core (MS06) was collected in 2007 about 2.3 km offshore Augusta at a water depth of 72 m below sea level. Core MS06 consisted of a 6.7 m long sequence that included 12 anomalous intervals interpreted as the primary effect of tsunami backwash waves in the last 4500 years. In this study, tsunami deposits were identified, based on sedimentology and displaced benthic foraminifera (as for core MS06) reinforced by X-ray fluorescence data. Two erosional surfaces (L1 and L2) were recognized coupled with grain size increase, abundant Posidonia oceanica seagrass remains and a significant amount of Nubecularia lucifuga, an epiphytic sessile benthic foraminifera considered to be transported from the inner shelf. The occurrence of Ti/Ca and Ti/Sr increments, coinciding with peaks in organic matter (Mo inc/coh) suggests terrestrial run-off coupled with an input of organic matter. The L1 and L2 horizons were attributed to two distinct historical tsunamis (AD 1542 and AD 1693) by indirect age-estimation methods using 210Pb profiles and the comparison of Volume Magnetic Susceptibility data between MG cores and MS06 cores. One most recent bioturbated horizon (Bh), despite not matching the above listed interpretative features, recorded an important palaeoenvironmental change that may correspond to the AD 1908 tsunami. These findings reinforce the value of offshore sediment records as an underutilized resource for the identification of past tsunamis.
    Beschreibung: Published
    Beschreibung: 1553-1576
    Beschreibung: 6T. Studi di pericolosità sismica e da maremoto
    Beschreibung: JCR Journal
    Schlagwort(e): Eastern Sicily ; tsunami ; foraminifera ; sedimentology ; XRF core scanning ; 04.04. Geology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 14
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    Homogenization in Terms of Mw of Local Magnitudes of Italian Earthquakes That Occurred before 1981 (2018)
    Seismological Society of America
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    Publikationsdatum: 2018-02-16
    Beschreibung: In the last two decades, several studies addressed the revaluation and homogenization of the Italian instrumental seismic catalog, but all of them refer to the time interval from 1981, that is, the starting year of the Catalogo Strumentale dei Terremoti Italiani (CSTI). At the time, the CSTI was conceived as the continuation of the catalog of the Progetto Finalizzato Geodinamica (PFG) but, over time, the PFG catalog was almost totally forgotten, and presently it is even difficult to obtain because it is not provided by any website. In this work, we integrate a genuine copy of PFG, with additional locations from the bulletins of the Istituto Nazionale di Geofisica (ING, now known as INGV) and of the International Seismological Centre (ISC) and with local magnitudes from two couples of Wood–Anderson (WA) seismometers operational in Italy in the 1970s and 1980s, mostly derived from a careful scrutiny of paper bulletins of the Osservatorio Geofisico Sperimentale (OGS) and of the ING. We restrict our analysis to the time interval from 1960 to 1980 because, based on various evidence, we can infer that within such period most instrumental magnitudes reported by the PFG catalog are reasonably coherent with the Richter’s definition. Magnitudes provided by WA stations and other data sources are calibrated with respect to Mw by general orthogonal regressions. The final catalog from 1960 to 1980 contains 8536 earthquakes, of which we compute a true or proxy Mw magnitude with related uncertainty for 6407. The analysis of the frequency–magnitude distribution indicates completeness for about Mw ≥4:0. This work extends the time coverage of the Italian instrumental catalog to about 55 yrs before the present, allowing the statistical study of some important seismic periods that occurred, for example, in 1962 (Irpinia), 1968 (Belice Valley), 1976 (Friuli), 1979 (Umbria), and 1980 (Irpinia).
    Beschreibung: Published
    Beschreibung: 481–492
    Beschreibung: 4IT. Banche dati
    Beschreibung: JCR Journal
    Schlagwort(e): local magnitude ; magnitude homogenization ; 04.06. Seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 15
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    Gempa Nusantara: A New Digital Database of Felt Intensity for Historical Earthquakes in the Indonesian Archipelago (2018)
    Seismological Society of America
    Details
    Publikationsdatum: 2021-11-08
    Beschreibung: Seismicity during Dutch colonial rule in Indonesia between 1800 and 1939 is poorly catalogued with existing summaries (e.g. Newcomb & McCann, 1987) too brief for further quantitative assessment such as the calculation of intensity magnitudes (MI). We focus on this period in Indonesian history, collating and analysing reports from official documents and newspapers from the erstwhile Dutch East Indies. We scrutinize these for macroseismic intensity using the European Macroseismic Scale (EMS-98). This scale is closely related to the Modified Mercalli Intensity (MMI) scale but is associated with better guidelines with which to assess damage to built-up environments. Our approach enables us to uniformly assess felt intensities from Sumatra, Java, Bali, and Borneo along with instances of perceived shaking from the eastern Indonesian archipelago, and from the Malay peninsula including Singapore. Building upon previous work (Martin et al., 2015), we corelate our data, when possible, with regional, and teleseismic instrumental observations. This allows us to discriminate, for example, a possible M~6 doublet in the region of South Sumatra in 1908. Felt effects in west Malaysia and Singapore from numerous earthquakes in Sumatra were also collected, and unexpectedly, we found two widely felt earthquakes in Singapore in 1922 that likely originated in the region of the southern Malaya peninsula. All our observations contribute to a database named Gempa Nusantara which roughly translates to earthquakes (gempa) in the Indonesian archipelago (nusantara) in Bahasa Indonesia. This database uses a web application called MIDOP (Macroseismic Intensity Data Online Publisher) which is an open-source program written in PHP that has been previously utilized to publish intensity data in Europe (Locati et al., 2014). In our study we extend the capabilities of the MIDOP application further, particularly in equatorial regions, and use it to manage our data from historical Indonesian earthquakes.
    Beschreibung: Earth Observatory of Singapore, Nanyang Technological University
    Beschreibung: Published
    Beschreibung: Miami, Florida, United States of America
    Beschreibung: 4T. Sismicità dell'Italia
    Beschreibung: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica
    Schlagwort(e): historical seismology ; macroseismic intensity ; 04. Solid Earth ; 04.04. Geology ; 04.06. Seismology ; 05.02. Data dissemination
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Poster session
    Standort Signatur Erwartet Verfügbarkeit
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    A metagenomic assessment of winter and summer bacterioplankton from Antarctica Peninsula coastal surface waters (2012)
    Nature Publishing Group
    Details
    Publikationsdatum: 2022-05-26
    Beschreibung: © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in The ISME Journal 6 (2012): 1901-1915, doi:10.1038/ismej.2012.31.
    Beschreibung: Antarctic surface oceans are well-studied during summer when irradiance levels are high, sea ice is melting and primary productivity is at a maximum. Coincident with this timing, the bacterioplankton respond with significant increases in secondary productivity. Little is known about bacterioplankton in winter when darkness and sea-ice cover inhibit photoautotrophic primary production. We report here an environmental genomic and small subunit ribosomal RNA (SSU rRNA) analysis of winter and summer Antarctic Peninsula coastal seawater bacterioplankton. Intense inter-seasonal differences were reflected through shifts in community composition and functional capacities encoded in winter and summer environmental genomes with significantly higher phylogenetic and functional diversity in winter. In general, inferred metabolisms of summer bacterioplankton were characterized by chemoheterotrophy, photoheterotrophy and aerobic anoxygenic photosynthesis while the winter community included the capacity for bacterial and archaeal chemolithoautotrophy. Chemolithoautotrophic pathways were dominant in winter and were similar to those recently reported in global ‘dark ocean’ mesopelagic waters. If chemolithoautotrophy is widespread in the Southern Ocean in winter, this process may be a previously unaccounted carbon sink and may help account for the unexplained anomalies in surface inorganic nitrogen content.
    Beschreibung: CSR was supported by an NSF Postdoctoral Fellowship in Biological Informatics (DBI-0532893). The research was supported by National Science Foundation awards: ANT 0632389 (to AEM and JJG), and ANT 0632278 and 0217282 (to HWD), all from the Antarctic Organisms and Ecosystems Program.
    Schlagwort(e): Antarctic bacterioplankton ; Metagenomics ; Chemolithoautotrophy
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Format: application/msword
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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