28 research outputs found
Performances of the UNDERground SEISmic array for the analysis of seismicity in Central Italy
This paper presents the first results from the operation of a dense seismic array deployed in the underground
Physics Laboratories at Gran Sasso (Central Italy). The array consists of 13 short-period, three-component seismometers
with an aperture of about 550 m and average sensor spacing of 90 m. The reduced sensor spacing,
joined to the spatially-white character of the background noise allows for quick and reliable detection of coherent
wavefront arrivals even under very poor SNR conditions. We apply high-resolution frequency-slowness and
polarization analyses to a set of 27 earthquakes recorded between November, 2002, and September, 2003, at epicentral
distances spanning the 20-140 km interval. We locate these events using inversion of P- and S-wave backazimuths
and S-P delay times, and compare the results with data from the Centralized National Seismic Network
catalog. For the case of S-wave, the discrepancies among the two set of locations never exceed 10 km; the largest
errors are instead observed for the case of P-waves. This observation may be due to the fact that the small array
aperture does not allow for robust assessment of waves propagating at high apparent velocities. This information
is discussed with special reference to the directions of future studies aimed at elucidating the location of
seismogenetic structures in Central Italy from extended analysis of the micro-seismicity
Slow earthquakes and low frequency tremor along the Apennines, Italy
This paper reviews the main observations on slow earthquakes and low frequency tremor made along the Apennines,
the main seismic active zone of Italy. These observations have been made using a geodetic interferometer
system operating since 1994 in the underground tunnel of Gran Sasso, central Italy, and an underground seismic
array (UNDERSEIS) operating since 2002 in the same environment.
The observations made in recent years indicate that both phenomena are quite rare and apparently uncorrelated.
Slow earthquakes, mainly recorded in 1997 and occasionally later, have probably been caused by the activity of
a shallow fault system located near the interferometers. Until now only one tremor episode characterized by low
frequency content and duration of several hours has been detected in January 2004, without any correlations with
the occurrence of slow or regular earthquakes. The signal to noise ratio of this event is very low, but the results
of our detailed analysis show that its frequency contents and wave field characteristics are compatible with a low
frequency non volcanic tremor
Performances of the UNDERground SEISmic array for the analysis of seismicity in Central Italy
This paper presents the first results from the operation of a dense seismic array deployed in the underground Physics Laboratories at Gran Sasso (Central Italy). The array consists of 13 short-period, three-component seis- mometers with an aperture of about 550 m and average sensor spacing of 90 m. The reduced sensor spacing, joined to the spatially-white character of the background noise allows for quick and reliable detection of coher- ent wavefront arrivals even under very poor SNR conditions. We apply high-resolution frequency-slowness and polarization analyses to a set of 27 earthquakes recorded between November, 2002, and September, 2003, at epi- central distances spanning the 20-140 km interval. We locate these events using inversion of P- and S-wave back- azimuths and S-P delay times, and compare the results with data from the Centralized National Seismic Network catalog. For the case of S-wave, the discrepancies among the two set of locations never exceed 10 km; the largest errors are instead observed for the case of P-waves. This observation may be due to the fact that the small array aperture does not allow for robust assessment of waves propagating at high apparent velocities. This informa- tion is discussed with special reference to the directions of future studies aimed at elucidating the location of seismogenetic structures in Central Italy from extended analysis of the micro-seismicity
Ceres, as mulheres e o sertão: representações sobre o feminino e a agricultura brasileira na primeira metade do século XX
A Study of the Validity and Reliability of Forms H and J of the Miller Analogies Test
Abstract not availabl
High resolution velocity structure beneath Mount Vesuvius from seismic array data
A high resolution P-wave image of Mt. Vesuvius edifice has been derived from simultaneous inversion of travel times and hypocentral parameters of local earthquakes, land based shots and small aperture array data. The results give details down to 300 – 500 m. The relocated local seismicity appears to extend down to 5 km below the central crater, distributed in a major cluster, centered at 3 km below the central crater and in a minor group, with diffuse hypocenters inside the volcanic edifice. The two clusters are separated by an anomalously high Vp region at around 1 km depth. A zone with high Vp/Vs in the upper layers is interpreted as produced by the presence of intense fluid circulation. The highest energy quakes (up to M = 3.6) are located in the deeper cluster, in a high P-wave velocity zone. Our results favor an interpretation in terms of absence of shallow magma reservoirs.Published3.1. Fisica dei terremotiJCR Journalreserve
The role of academic education in increasing the awareness of physical education significance in health promotion: insights from TFA and PAS courses
The abstract summarizes the results of a study presented in the PEDAGOGY Oral Session of the SISMES IX NATIONAL CONGRESS - Brescia, September 29\u2013October 1 2017. The study was conducted on the keywords, categorized in 9 groups, of 331 final project works (TFA = 136; PAS = 195)
High resolution velocity structure beneath Mount Vesuvius from seismic array data
A high resolution P-wave image of Mt. Vesuvius edifice has been derived from simultaneous inversion of travel times and hypocentral parameters of local earthquakes, land based shots and small aperture array data. The results give details down to 300 – 500 m. The relocated local seismicity appears to extend down to 5 km below the central crater, distributed in a major cluster, centered at 3 km below the central crater and in a minor group, with diffuse hypocenters inside the volcanic edifice. The two clusters are separated by an anomalously high Vp region at around 1 km depth. A zone with high Vp/Vs in the upper layers is interpreted as produced by the presence of intense fluid circulation. The highest energy quakes (up to M = 3.6) are located in the deeper cluster, in a high P-wave velocity zone. Our results favor an interpretation in terms of absence of shallow magma reservoirs
Eziopatogenesi e manifestazioni cliniche della sindrome di Crouzon: revisione della letteratura
Objectives: The term Craniofacial dysostosis (CFD) is used to describe familiar forms of synostosis involving different sutures of the cranial base and midface. The aim of this work consists in a systematic review of literature on aetiology, etiopathogenesis, epidemiology, diagnosis, clinical, systemic, and oral manifestations and therapeutic options of Crouzon syndrome. Materials and methods: A systematic review of literature through Medline data bank [www.ncbi.nim.nih.gov/pubmed] was done using "Craniofacial Dysostosis", "Craniosynostosis", and "Crouzon Syndrome" as keywords. Results: Crouzon syndrome is the most common craniosynostosis. It develops after an early fusion of superior and posterior sutures of the maxilla with orbital ones, with consequent underdevelopment of the midface and ocular proptosis. Oral manifestations are maxillary hypoplasia, maxillary dental crowding, ogival palatus, and relative mandibular prognathism. Diagnosis can be done either through the evaluation of clinical phenotypes or DNA analysis with polymerase chain reaction (PCR). Treatment is mainly surgical. Orthodontic therapy is performed during the early skeletal maturation. Conclusions: Thanks to the important innovations in surgical techniques and to a muldisciplinary approach, patients affected by this syndrome may aspire to normal cerebral development, physical status, and social relationships