ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    facet.materialart.
    Unbekannt
    Tornillos at Vulcano: Clues to the dynamics of the hydrothermal system (2010)
    Elsevier
    Details
    Publikationsdatum: 2020-11-12
    Beschreibung: The number of tornillo events has recently increased at the Vulcano Island, Italy. While only 15 tornillos were recorded during 2004–2006, 584 events occurred in 2007–2008. They were located just below La Fossa Crater at depths ranging between 0.1 and 1 km b.s.l. During two intervals in 2007–2008 increases in the number of tornillos took place at the same time as temperature and geochemical anomalies were observed. The spectral content of the tornillos, generally characterized by one–two dominant spectral peaks near 6 and 10 Hz, varied over time, with changes also noted in the quality factors. The simplest source mechanism proposed for tornillos is the free eigenvibration of a fluid volume within a crack or a conduit. Based on this model, we propose a causal relationship between the temperature and geochemical anomalies and the increases in numbers of tornillos. As the amount of hydrothermal fluids increases during the anomalies, the upward flux of fluids grows. The consequent changes in the pressure, temperature and dynamics of the system of cracks and conduits result in the generation of tornillos. Based on the fluid-filled crack/conduit model, the shallow depths of the sources and the values of the quality factors, the fluid within the resonant crack/conduit was inferred to be an ash–gas or water droplet–gas mixture. Moreover, the observed variations in the wavefield can be caused by small changes in the location of the source, in the source mechanism, or in the medium in between the source and the seismic station. Finally, another peculiar feature of tornillos is the amplitude modulation that can be explained as a result of a beating phenomenon.
    Beschreibung: Published
    Beschreibung: 377-393
    Beschreibung: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Tornillos ; Vulcano Island ; Hydrothermal system ; Volcano seismology ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 2
    facet.materialart.
    Unbekannt
    Sismicità all’Etna tra Luglio 2005 e Gennaio 2006: evidenze di intrusione magmatica e di dinamica di fianco (2009)
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Nel presente lavoro sono presentati i risultati di uno studio della sismicità dell’Etna registrata tra Luglio 2005 e Gennaio 2006. Durante tale periodo l’integrazione dei dati provenienti da un esperimento condotto attraverso l’impiego di 20 stazioni temporanee a larga banda in aggiunta alla rete permanente, costituita da 40 stazioni, ha permesso di ottenere migliori localizzazioni ipocentrali (maggior numero di letture P ed S, riduzione degli errori ipocentrali e del gap azimutale). Ciò ha consentito analisi di maggior dettaglio anche degli eventi a più bassa magnitudo (M〈2.0) che costituiscono il 75 % del campione. In particolare, si è proceduto alla rilocalizzazione degli eventi (Fig. 1) utilizzando il modello di velocità 3D di Patanè et al. (2006) e al calcolo dei meccanismi focali. La maggior parte della sismicità è localizzata sul fianco orientale del vulcano permettendo una più accurata interpretazione della dinamica di questo settore. Inoltre, la localizzazione 3D dei terremoti ha meglio evidenziato l’attività sismica lungo il Rift meridionale del vulcano relativa ad uno sciame profondo (tra 10 e 15 km) registrato nell’agosto del 2005, probabilmente correlata ad una intrusione magmatica. Infatti, tale sismicità è stata seguita nei mesi successivi da un forte incremento del tremore che, tuttavia, non ha portato nel breve termine ad alcuna eruzione. Ciò nonostante, è stato osservato che in altri periodi la sismicità lungo questo trend strutturale ha preceduto di alcuni mesi l’attività eruttiva (2001, 2002-2003 e 2008).
    Beschreibung: Published
    Beschreibung: Rome
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; seismicity ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Oral presentation
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 3
    facet.materialart.
    Unbekannt
    Installazione di 5 stazioni digitali a larga-banda sull’isola di vulcano: un contributo alla conoscenza della sismicità superficiale della fossa (2009)
    INGV
    Details
    Publikationsdatum: 2020-02-24
    Beschreibung: Earthquakes beneath Vulcano (Aeolian Island, Italy) are associated with fracturing (single events and sporadic swarms of low magnitude) or related to processes of the geothermal system (Montalto, 1994). This latter processes is responsible for most of the background activity, which is represented by weak events originating at shallow depth under the La Fossa cone (H〈1.5 Km below sea level). In order to improved the Permanent Seismic Network (PSN) run by Catania Section of Istituto Nazionale di Geofisica e Vulcanologia (INGV-CT) by installing additional 5 broad-band stations surrounding the La Fossa crater, to. In particular, on November 2005 along the north rim of La Fossa cone, 3 digital stations were installed with an array configuration; thereafter, in spring 2007 another two stations were installed at the southern base of the cone. All the stations are currently in continual transmission with Lipari Observatory. We considered about 1200 micro-earthquakes recorded from January 2004 to July 2007 associated with fluid dynamics processes. Studying 1007 of these events, six classes of events have been recognized by visual inspection, spectral and cross correlation analyses. Three episodes of increasing occurrence accompanying geothermal and geochemical anomalies have been recorded during this time period. The improved seismic network allowed the location of 55 events with unprecedented resolution and to highlight a space distribution depending on the classes of events. The events are located in the central and south-oriental sector of the cone at 500-1000 meter b.s.l. depth and events of each class seem clustering in preferential sectors.
    Beschreibung: Published
    Beschreibung: 1-16
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: N/A or not JCR
    Beschreibung: open
    Schlagwort(e): Seismicity ; La Fossa ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 4
    facet.materialart.
    Unbekannt
    Multiparametric Approach in Investigating Volcano-Hydrothermal Systems: the Case Study of Vulcano (Aeolian Islands, Italy) (2012)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Seismic activity, ground deformation, and soil and fumarole temperatures acquired during 2004–2007 at Vulcano (Aeolian Islands) are analysed and the time relations among the different time series are discussed. Changes in temperature of fumarolic gases took place during four ‘‘anomalous’’ periods (November 2004–March 2005; October 2005–February 2006; August–October 2006; July–December 2007) at the same time as an increasing number of volcano-seismic events. In particular, the temperatures at high temperature vents and at steam heated soil ranged in time from 180 to 440 C and from 20 to 90 C, respectively. The maximum daily number of volcano-seismic events was 57, reached during the second anomalous period. This seismicity, characterised by focal depth generally lower than 1 km below sea level (b.s.l.) and composed of different kinds of events associated to both resonance and shear failure processes, is related to the shallow dynamics of the hydrothermal system. During the analysed period, very few volcano-tectonic earthquakes took place and tilt recordings showed no sharp or important changes. In light of such observations, the increases in both temperature and volcano-seismic events number were associated to increases in the release of gas from a deep and stable magma body, without magma intrusions within the shallow hydrothermal system. Indeed, a greater release of gas from depth leads to increased fluid circulation, that can promote increases in volcano-seismic events number by both fracturing processes and resonance and vibration in cracks and conduits. The different trends observed in the measured geochemical and geophysical series during the anomalous periods can be due to either time changes in the medium permeability or a changing speed of gas release from a deep magma body. Finally, all the observed variations, together with the changing temporal distribution of the different seismic event kinds, suggest that the hydrothermal system at Vulcano can be considered unsteady and dynamic.
    Beschreibung: Published
    Beschreibung: 167–182
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Volcano seismolog ; soil and fumarole temperatures ; tilt data ; hydrothermal system ; Vulcano Island ; volcanic unrest ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 5
    facet.materialart.
    Unbekannt
    Time-space variation of volcano-seismic events at La Fossa (Vulcano, Aeolian Islands, Italy): new insights into seismic sources in a hydrothermal system (2010)
    Springer
    Details
    Publikationsdatum: 2020-02-24
    Beschreibung: We investigated the relationship between volcano-seismic events, recorded at La Fossa crater of Vulcano (Aeolian Islands, Italy) during 2004-2006, and the dynamics of the hydrothermal system. During the period of study, three episodes of increasing numbers of volcano-seismic events took place at the same time as geothermal and geochemical anomalies were observed. These geothermal and geochemical anomalies have been interpreted as resulting from an increasing deep magmatic component of the hydrothermal fluids. Three classes of seismic events (long period, high frequency and monochromatic events), characterised by different spectral content and various similarity of the waveforms, have been recognised. These events, clustered mainly below La Fossa crater area at depths of 0.5–1.1 km b.s.l., were space-distributed according to the classes. Based on their features, we can infer that such events at Vulcano are related to two different source mechanisms: (1) fracturing processes of rocks and (2) resonance of cracks (or conduits) filled with hydrothermal fluid. In the light of these source mechanisms, the increase in the number of events, at the same time as geochemical and geothermal anomalies were observed, was interpreted as the result of an increasing magmatic component of the hydrothermal fluids, implying an increase of their flux. Indeed, such variation caused an increase of both the pore pressure within the rocks of the volcanic system and the amount of ascending fluids. Increased pore pressures gave rise to fracturing processes, while the increased fluid flux favoured resonance and vibration processes in cracks and conduits. Finally, a gradual temporal variation of the waveform of the hybrid events (one of the subclasses of long period events) was observed, likely caused by heating and drying of the hydrothermal system.
    Beschreibung: Published
    Beschreibung: 803-816
    Beschreibung: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Volcano seismology ; Vulcano Island ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...