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Olivieri, Marco
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Olivieri, Marco
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marco.olivieri@ingv.it
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44 results
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- PublicationRestrictedτ_p^max magnitude estimation, the case of the April 6, p 2009 L’Aquila Earthquake(2013)
; ;Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, ItaliaRapid magnitude estimate procedures represent a crucial part of proposed Earthquake Early Warning Systems. Most of these estimates are fo- cused on the first part of the P-wave train, the earlier and less destructive part of the ground motion that follows an earthquake. Allen and Kanamori [2003] proposed to use the predominant period of the P-wave to determine the magnitude of a large earthquake at local distance and Olivieri et al. [2008] calibrated a specific relation for the Italian region. The Mw 6.3 earthquake that hit Central Italy on April 6, 2009 and the largest aftershocks provide a useful dataset to validate the proposed relation and discuss the risks con- nected to the extrapolation of magnitude relations with a poor dataset of large earthquake waveforms. A large discrepancy between ML estimated by means of τ max evaluation and standard ML (6.8 ± 1.5 vs. 5.9 ± 0.4) suggests using p caution when ML vs. τmax calibrations do not include a relevant dataset of p large earthquakes. Effects from large residuals could be mitigated or removed introducing selection rules on τ function, by regionalizing the ML vs. τmax pp function in the presence of significant tectonic or geological heterogeneity, and using probabilistic and evolutionary methods.245 28 - PublicationOpen AccessCOVID-19 lockdown and its latency in Northern Italy: seismic evidence and socio-economic interpretation(2020-10-05)
; ; ; ; ; ; ; ; ; ; ; ; ; The Italian Government has decreed a series of progressive restrictions to delay the COVID-19 pandemic diffusion in Italy since March 10, 2020, including limitation in individual mobility and the closure of social, cultural, economic and industrial activities. Here we show the lockdown effect in Northern Italy, the COVID-19 most affected area, as revealed by noise variation at seismic stations. The reaction to lockdown was slow and not homogeneous with spots of negligible noise reduction, especially in the first week. A fresh interpretation of seismic noise variations in terms of socio-economic indicators sheds new light on the lockdown efficacy pointing to the causes of such delay: the noise reduction is significant where non strategic activities prevails, while it is small or negligible where dense population and strategic activities are present. These results are crucial for the a posteriori interpretation of the pandemic diffusion and the efficacy of differently targeted political actions.512 15 - PublicationRestrictedEmpirical mode decomposition of long-term polar motion observation(2015)
; ; ; ;Spada, G.; Dip.to di Scienze di Base e Fondamenti, Università di Urbino, Urbino, Italy ;Galassi, G.; Dipartimento di Scienze di Base e Fondamenti, Urbino University “Carlo Bo” ;Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; ; We use the Empirical Mode Decomposition (EMD) method to study the decadal variations in polar motion and its long-term trend since year 1900. The existence of the so-called “Markowitz wobble”, a multidecadal fluctuation of the mean pole of rotation whose nature has long been debated since its discovery in 1960, is confirmed. In the EMD approach, the Markowitz wobble naturally arises as an empirical oscillatory term in polar motion, showing significant amplitude variations and a period of approximately 3 decades. The path of the time-averaged, non-cyclic component of polar motion matches the results of previous investigations based on classical spectral methods. However, our analysis also reveals previously unnoticed steep variations (change points) in the rate and the direction of secular polar motion.420 84 - PublicationOpen AccessElarmS and the next large earthquake in Italy(2008)
; ; ; ;Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Basili, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Allen, R. M.; ; We evaluate the capability of ElarmS to work as an Early Warning System for the next destructive earthquake in Italy. Potential sources were retrieved from the Database of Individual Seismogenic Sources (DISS; http://www.ingv.it/DISS/) and from the catalogue of historical earthquakes (CPTI04; http://emidius.mi.ingv.it/CPTI/). Based on the geometry of the new Italian Broad-Band Seismic Network, we estimate the "Alert time" for each source from different nucleation points and the size of the shadow zone, the area already affected by S-waves. We present our results for peninsular Italy with a particular attention to the metropolitan areas of Napoli, (Southern Italy) that have been selected as a test site for the SAFER project (http://www.saferproject.net/), plus Roma and Firenze.183 324 - PublicationOpen AccessA new System for Earthquake Detection and Source Parameters Determination in Italy(2008-08-07)
; ; ; ; ; ; ; ;Mazza, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Mele, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Pintore, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Quintiliani, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Scognamiglio, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Selvaggi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; ; ; ; ; ; ; ; ;Papadopoulos, G.; NOA, GreeceA new agreement between the Italian Istituto Nazionale di Geofisica e Vulcanologia (INGV) and the Italian Civil Protection Agency drove (o inspired) a new effort towards the implemen- tation of a robust, reliable and efficient system for real time seismic monitoring of the Italian country and the surrounding regions. Earthworm has been configured as the automatic processing system to analyze the signals of the Italian National Seismic Network that counts today more than (??? 230 ???) stations equipped with broad-band, very-broad-band and short period instruments. Such realization required a fine tuning of several modules to account for the specificity of the Italian Case, where various earthquake scenarios appear few tens of kilometers apart such as shallow crustal seismicity in the Apennines, and deep and very deep earthquakes in the southern Tyr- rhenian sea. We will present and discuss the proposed schema and the results of the extensive test based on the optimal configuration in terms of accuracy and rapidness166 410 - PublicationOpen AccessThe Mediterranean broad band seismographic network(2005-09-11)
; ; ; ; ;Mazza, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Mandiello, A. G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Casale, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; ; ; ; ;Advanced Research Workshop -, - NatoAdvanced Research Workshop -, - NatoThe Mediterrean Network (MedNet) presently comprises 22 operating broadband seismic stations installed and maintained in cooperation with 13 geophysical institutions in Italy and in most of the countries adjacent to Mediterranean Sea. The number of stations may vary as stations are opened or sometimes closed due to different reasons like political, technical, etc., but usually temporarily. All the stations are equipped with Quanterra digitizers and Streckeisen sensors, mostly STS2 with a few STS1. Aim of the network is to contribute to monitoring of one of the most active seismic regions of the World in terms of providing high quality real-time broadband data to the seismological community. Operations started with off-line field data collection and dial-up capabilities were later added at selected sites. At present these have been replaced with more efficient TCP connections that provide for real-time data collection over the whole network. This important technological upgrade allows a prompt contribution to the seismic monitoring of Italy and of most countries bordering the Mediterranean Sea, since data are exchanged in real-time with other seismological observatories. SeedLink protocol has been adopted for transmission. As for data archiving and distribution, a fast system for retrieving data has been developed. Continuous data streams, collected both from field data tapes and from real time transfer, are stored at the MedNet Data Center and are directly available at users’ request by the standard AutoDRM and NetDC protocols (in GSE and SEED formats respectively). Station metadata and continuous waveforms are archived in a MySQL database on RAID systems and backed up on DLT tapes. Presently, fully automatic network functions include: daily monitoring of state of health; triggered retrieval of event waveforms (with magnitude- and region- specific selection criteria), local and surface wave magnitude determination, and update of web pages (http://mednet.ingv.it) for events and station information. Rapid semiautomatic moment tensor solutions are calculated by means of a modified Harvard technique, which lowers the Mw threshold down to 4.5 for regional events in those areas with proper station coverage. For smaller earthquakes in Italy a new approach to moment tensor estimation, based on higher signal frequencies, is now being developed. Preliminary tests on earthquake recordings (not only MedNet stations) from the 2002 Molise, South Italy sequence have proved very successful.204 474 - PublicationRestrictedA heuristic evaluation of long-term global sea-level acceleration(2015)
; ; ; ;Spada, G.; Dip.to di Scienze di Base e Fondamenti, Università di Urbino, Urbino, Italy ;Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Galassi, G.; Dip.to di Scienze di Base e Fondamenti, Università di Urbino, Urbino, Italy; ; In view of the scientific and social implications, the global mean sea-level rise (GMSLR), its possible causes and future trend have been a challenge for long. For the 20th century, reconstructions generally indicate a rate of GMSLR in the range of 1.5 to 2.0 mm yr−1. However, the existence of non-linear trends is still debated, and current estimates of the secular acceleration are subject to ample uncertainties. Here we use various GMSLR estimates published on scholarly journals since the 40’s for a heuristic assessment of global sea-level acceleration. The approach, alternative to sea-level reconstructions, is based on simple statistical methods and exploits the principles of meta-analysis. Our results point to a global sea-level acceleration of 0.54±0.27 mm/year/century (1σ) between 1898 and 1975. This supports independent estimates and suggests that a sea-level acceleration since the early 1900’s is more likely thancurrently believed.413 167 - PublicationRestrictedCalving event detection by observation of seiche effects on the Greenland fjords(2013)
; ; ; ;Walter, F.; Swiss Seismological Service, ETH Zürich, Switzerland; Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zürich, Switzerland ;Olivieri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia ;Clinton, J.; Swiss Seismological Service, ETH Zürich, Switzerland; ; With mass loss from the Greenland ice sheet accelerating and spreading to higher latitudes, the quantification of mass discharge in the form of icebergs has recently received much scientific attention. Here, we make use of very low frequency (0.001-0.01 Hz) seismic data from three permanent broadband stations installed in the summers of 2009/2010 in northwest Greenland in order to monitor local calving activity. At these frequencies, calving seismograms are dominated by a tilt signal produced by local ground flexure in response to fjord seiching generated by major iceberg calving events. A simple triggering algorithm is proposed to detect calving events from large calving fronts with potentially no user interaction. Our calving catalogue identifies spatial and temporal differences in calving activity between Jakobshavn Isbræ and glaciers in the Uummannaq district some 200 km further north. The Uummannaq glaciers show clear seasonal fluctuations in seiche-based calving detections as well as seiche amplitudes. In contrast, the detections at Jakobshavn Isbræ show little seasonal variation, which may be evidence for an ongoing transition into winter calving activity. The results offer further evidence that seismometers can provide efficient and inexpensive monitoring of calving fronts.608 94 - PublicationOpen AccessThe optical, seismic, and infrasound signature of the March 5 2022, bolide over Central Italy(2023)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; On March 5, 2022, a 12 kg meteoroid crossed the sky above Central Italy and was observed by three different observational systems: the PRISMA all-sky camera network (10 stations), the Italian national seismic network (61 stations), and a 4-element infrasound array. The corresponding datasets, each with its own resolution, provided three independent assessments of the trajectory, size and speed of the meteoroid. The bolide traveled across central Italy with an azimuth of 102 degrees, becoming visible at about 91 km above sea level with a velocity of about 15.4 km/s. Its visible trajectory lasted about 15 s. Reasonably, the residual portion of the ablated bolide terminated its path in the Adriatic Sea and could not be recovered. Seismic and infrasound data well match optical observations detecting the bolide Mach cone at 68 km above sea level with a back azimuth of 25 degrees with respect to the array. By comparing results from the three different systems, discrepancies are within the estimated uncertainties, thus confirming the mutual consistency of the adopted methodologies. Therefore, this study shows that different approaches can be integrated to improve the detection capability for bolide crossing the sky in monitored regions.164 7 - PublicationOpen AccessSea-level trend variability in the Mediterranean during the 1993–2019 periodSea-level change is one of the most concerning climate change and global warming consequences, especially impacting coastal societies and environments. The spatial and temporal variability of sea level is neither linear nor globally uniform, especially in semi-enclosed basins such as the Mediterranean Sea, which is considered a hot spot regarding expected impacts related to climate change. This study investigates sea-level trends and their variability over the Mediterranean Sea from 1993 to 2019. We use gridded sea-level anomaly products from satellite altimetry for the total observed sea level, whereas ocean temperature and salinity profiles from reanalysis were used to compute the thermosteric and halosteric effects, respectively, and the steric component of the sea level. We perform a statistical change point detection to assess the spatial and temporal significance of each trend change. The linear trend provides a clear indication of the non-steric effects as the dominant drivers over the entire period at the Mediterranean Sea scale, except for the Levantine and Aegean sub-basins, where the steric component explains the majority of the sea-level trend. The main changes in sea-level trends are detected around 1997, 2006, 2010, and 2016, associated with Northern Ionian Gyre reversal episodes, which changed the thermohaline properties and water mass redistribution over the sub-basins.
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