ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Large amplification of ground motion at rock sites within a fault zone in Nocera Umbra (central Italy) (2000)
    Springer
    Journal of seismology 4 (2000), S. 543-554 
    Details
    ISSN: 1573-157X
    Keywords: fault zone ; ground motion ; Nocera Umbra ; site effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract During the two mainshocks of September 26, 1997 inthe Umbria-Marche border a strong-motion accelerographrecorded peak ground accelerations as large as 0.6 g,approximately, in the town of Nocera Umbra, atdistances of 10 to 15 km from the epicentres. Thisvalue is significantly larger than expected on thebasis of the usual regressions with magnitude anddistance. A broad-band amplification up to a factor of10 was consistently estimated in previous papers,using both weak and strong motion data recorded at theaccelerograph site during local moderate earthquakes.To study the cause of this amplification we deployedsix seismologic stations across the tectonic contactbetween the Ceno-Mesozoic limestone and the Mesozoicmarly sandstone where the accelerograph is installed.Seismograms of 21 shallow aftershocks in the magnituderange from 2.2 to 4.0 and a subcrustal Mw = 5.3event are analysed. Regardless of epicentre location,waveforms show a large complexity in an approximately200 m wide band adjacent to the tectonic contact. Thisis interpreted as the effect of trapped waves in thehighly fractured, lower velocity materials within thefault zone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026559901378
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    facet.materialart.
    Unknown
    Deep crustal roots beneath the northern Apennines inferred from teleseismic receiver functions (2007)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Teleseismic waveforms recorded by a regional array crossing the northern Italian peninsula and northern Corsica are analyzed using the receiver function technique, to determine the first order crustal structure. The receiver function approach is used to isolate receiver-side PS conversions generated at the crust-mantle boundary and any major velocity discontinuity beneath the stations. We used the time delay between the direct P wave and the PS wave converted at the Moho discontinuity to infer crustal thickness beneath the stations. The crust-mantle boundary is estimated at 25 ± 1 km of depth in northern Corsica, 20 ± 2 km beneath the Elba island and 20 to 24 ± 2 km beneath Tuscany. In the eastern portion of the array, Moho depth increases from 28 ± 2 km beneath the Adriatic coast to 49 ± 3 km beneath the Apennine chain, in a distance of about 100 km. A double PS conversion produced beneath the Val Tiberina graben, to the west of the Apennines, corresponds to interfaces as deep as 20 ± 2 and 52 ± 2 km. This observation supports the hypothesis of partial overlapping between the shallow Tuscan Moho and the deeper Adriatic Moho. The westward deepening of the Adriatic Moho beneath the northern Apennines can be explained by lithosphere delamination that has dragged downward the Adriatic lower crust. The deep crustal root estimated beneath the northern Apennines indicates that this portion of the chain is isostatically overcompensated.
    Description: Published
    Description: 69-78
    Description: JCR Journal
    Description: reserved
    Keywords: Teleseismic receiver functions ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    High-Frequency Wave Propagation from Mantle Earthquakes in the Tyrrhenian Sea: New Constraints for the Geometry of the south Tyrrhenian Subduction Zone (2007)
    AGU
    Details
    Publication Date: 2017-04-03
    Description: Propagation of shear waves produced by 25 mantle earthquakes (80-600 km depth) in the subduction zone of the south Tyrrhenian Sea (southern Italy) has been investigated to infer the geometry and extent of the descending lithosphere. From all hypocentral depths high-frequency, high-amplitude shear waves are recorded at most of the stations in southern Italy and easternmost Sicily. This shear-wave energy is interpreted to travel as a guided wave within the descending slab. In contrast, shear waves are either not recorded at all or they are recorded as low-frequency, low-amplitude signals at stations located in the peninsular part of Italy north of the Calabrian arc, in western Sicily and in Sardinia. This systematic S-wave attenuation is interpreted in terms of an active and continuous slab correlated with and limited to the Calabrian arc.
    Description: Published
    Description: 2877-2880
    Description: JCR Journal
    Description: reserved
    Keywords: Tyrrhenian subduction zone ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    The Adriatic lithosphere is a promontory of the African plate: Evidence of a continuous mantle lid in the Ionian Sea from efficient Sn propagation (2007)
    AGU
    Details
    Publication Date: 2017-04-04
    Description: Evidence of a continuous lithosphere between the northern margin of Africa and Italy is given from the analysis of regional waveforms recorded by the Italian Seismic Network. Frequency and amplitude of shear waves Sn propagating over the Ionian Sea and the western part of the Levantine Sea are examined in this study. An important observation is that Sn waves are efficiently transmitted without exception at epicentral distances ranging from 3˚ to 22.5˚. The very efficient propagation of uppermost mantle shear waves implies that mantle lithosphere is continuous in this part of the Mediterranean region. This in turn implies that the lithosphere underlying the Adriatic Sea is attached to the African lithosphere and can be considered a promontory of the major African plate. The regional shear phase Lg, that typically propagates within the continental crust, is not transmitted in this area. This observation is consistent with the presence of oceanic crust in the eastern Mediterranean, as hypothesized by previous studies.
    Description: Published
    Description: 431-434
    Description: JCR Journal
    Description: reserved
    Keywords: Sn waves propagation ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    Shear wave attenuation in the lithosphere beneath Italy and surrounding regions: Tectonic implications (2007)
    Agu
    Details
    Publication Date: 2017-04-04
    Description: More than 700 waveforms produced by 51 shallow earthquakes and recorded at regional distances (250-1400 km) by the Italian seismic network have been analyzed to characterize the amplitude and frequency contents of the crustal and uppermost mantle shear waves Lg and Sn, respectively. The crustal phase Lg efficiently propagates through the relatively stable Adriatic continental crust, while it is not observed along propagation paths crossing major physiographic features, like the Apennine chain and the basinal domain of the Tyrrhenian and Ionian Seas. Similar to Lg, efficient Sn propagation is observed in the uppermost mantle beneath the Po plain and the Adriatic Sea. Efficient Sn transmission is also observed across the northern Ionian Sea and Sicily and in the area between Sardinia and the northern coasts of Africa. Sn are efficiently transmitted across the Sicily Channel, and rather efficient Sn propagate beneath the Ligurian Sea. On the contrary, inefficient Sn transmission characterizes the uppermost mantle beneath the Apennines, the western margin of the Italian peninsula, and the southern Tyrrhenian Sea. Shear wave attenuation suggests the presence of asthenospheric material in the uppermost mantle, probably related to the present-day extension along the Apennine chain and in the Tyrrhenian basin. This interpretation is consistent with the presence of extensive Neogene and Quaternary volcanic activity in these areas and related high heat flow. Proposed lithospheric delamination processes beneath the Apennines and subduction beneath the Tyrrhenian Sea can reasonably explain the observed high-attenuation zones in the uppermost mantle. In contrast, a high-strength mantle lid is inferred to underlay the Po plain, the Adriatic Sea, and the northern Ionian Sea. The available waveforms also indicate that a continuous mantle lid is present beneath Sicily and the extensional domain of the Sicily Channel, as well as in the marine area south of Sardinia.
    Description: Published
    Description: 11,863-11,875
    Description: JCR Journal
    Description: open
    Keywords: Sn attenuation ; Italy ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 6
    facet.materialart.
    Unknown
    Lateral variations of Pn propagation in Italy: Evidence for a high attenuation zone beneath the Apennines (2007)
    Agu
    Details
    Publication Date: 2017-04-04
    Description: Pn phases recorded by 40 stations of the Italian seismic network are analyzed using the spectral ratio technique to estimate the Q structure of the uppermost mantle beneath the Italian peninsula and nearby Adriatic Sea. A total of 344 digital waveforms are analyzed from 22 earthquakes that occurred within distances of 300 to 1600 km. The calculated apparent Q values are grouped into two categories: Q 〉 800 characterizes the Adriatic side of the Italian peninsula, indicating that the Adriatic lithosphere is very efficient in propagating Pn phases through the uppermost mantle; Q 〈 600 characterizes the uppermost mantle beneath the Apennines and western Italy, indicating less efficient wave propagation. The presence of asthenospheric mantle material at shallow depths beneath the Apennines can explain the observed Q.
    Description: Published
    Description: 709-712
    Description: JCR Journal
    Description: open
    Keywords: Seismic attenuation ; Apennines ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 7
    facet.materialart.
    Unknown
    Suboceanic Rayleigh Waves in the 1755 Lisbon Earthquake (2010)
    Springer
    Details
    Publication Date: 2017-04-04
    Description: Moderate-magnitude shallow earthquakes in the Atlantic Ocean, hundreds of kilometres southwest of Lisbon, can generate efficient suboceanic Rayleigh waves (SRW) that are well recorded in Portugal. Here we compare moderate-size earthquakes recorded by seismic stations in Portugal with the Tyrrhenian Sea earthquakes recorded in peninsular Italy where SRW were recently observed. In spite of a different behaviour of high frequencies due to the different tectonic setting of the two areas, similar results are found in the intermediate-period range, suggesting that this effect, if extrapolated to a magnitude larger than 8, could be devastating at regional distance in terms of ground motion amplitude and duration. Through 1D models, we explore the hypothesis that the high level of destruction and the long duration of shaking felt during the Great 1755 Lisbon earthquake were caused by SRW. In this preliminary study, we check the role of critical model parameters. We find that duration and amplitude are largest when the average thickness of the water layer is 2 km and shear-wave velocity of the ocean floor is close to the speed of sound in the water. Both conditions are realistic for a source in the Atlantic Ocean, few hundreds of kilometres southwest of Lisbon. Moreover, the propagation of SRW at regional distances accounts for durations of more than ten minutes as the effect of a single large earthquake.
    Description: Published
    Description: 283-295
    Description: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Description: open
    Keywords: ground motion ; surface waves ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    Environmental pre-exploitation monitoring of Torre Alfina geothermal system (Central Italy) (2016)
    Details
    Publication Date: 2017-04-04
    Description: An interesting project of geothermal pilot plant, with no-gas emission in atmosphere, has been submitted for approval in the medium-enthalpy geothermal field of Torre Alfina. This prompted us to develop a geochemical and geophysical monitoring of the area with the aim of establishing a background information to reco-gnize anomalous gas emission, induced seismicity and subsidence, possibly related to the field exploitation. The exploration conducted by Enel in the years ‘70 - '80, including the drilling of 9 deep wells, has shown the existence of a medium-enthalpy geothermal field in the Torre Alfina zone, in central Italy. The area has been affected by a very complex geological evolution during the Neogene. It was affected by the Quaternary volcanism of the Tyrrhenian margin which, reached its climax between 0.6 and 0.3 Ma. The present stress field around Quaternary volcanoes of central Italy has a NE to ENE direction of extension, in agreement with the alignment of Quaternary volcanoes and earthquake fault plane solutions, with T axes preferentially oriented between NE and ENE.
    Description: Published
    Description: Prague, Czech Republic, June 22 to July 2, 2015
    Description: 6T. Sismicità indotta e caratterizzazione sismica dei sistemi naturali
    Description: open
    Keywords: Torre Alfina geothermal system ; pre-exploitation monitoring ; geothermal pilot plant ; geochemistry ; induced seismicity ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Poster session
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...