GLORIA

GEOMAR Library Ocean Research Information Access

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
    facet.materialart.
    Unknown
    The role of gravitational instabilities in deposition of volcanic ash (2015)
    GSA (Geological Society of America)
    In:  Geology, 43 (3). pp. 211-214.
    Details
    Publication Date: 2020-10-29
    Description: Volcanic ash is a significant hazard for areas close to volcanoes and for aviation. Gravitational instabilities forming at the bottom of spreading volcanic clouds have been observed in many explosive eruptions. Here we present the first quantitative description of the dynamics of such instabilities, and correlate this with the characteristics of the fall deposit from observations of the 4 May 2010 Eyjafjallajökull (Iceland) eruption. Gravitational instabilities initially took the form of downward-propagating fingers that formed continuously at the base of the cloud, and appeared to be advected passively at the crosswind speed. Measurements of finger propagation are consistent with initial conditions inferred from previous studies of ash cloud dynamics. Dedicated laboratory analogue experiments confirmed that finger downward propagation significantly exceeded the settling speed of individual particles, demonstrating that gravitational instabilities provide a possible mechanism for enhanced sedimentation of fine ash. Our observations challenge the view that aggregation is the primary explanation of proximal fine ash sedimentation, and give direct support for the role of gravitational instabilities in providing regions of high particle concentration that can promote aggregation.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1130/G36252.1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 2
    facet.materialart.
    Unknown
    Multiple hazards and paths to eruptions: A review of the volcanic system of Vulcano (Aeolian Islands, Italy) (2020)
    Elsevier
    Details
    Publication Date: 2020-10-07
    Description: Vulcano is one of the 7 volcanic islands and 6 seamounts forming the Aeolian volcanic district (Italy). Vulcano has a long eruptive record, and its last eruption (1888–90 AD) originated the definition of the Vulcanian eruptive style. Like most volcanic islands, Vulcano generates many potentially interconnected hazards, determining a potentially high risk. Here, we review the state of knowledge on its geology, eruptive activity, historical accounts, structural setting, geophysical and geochemical surveillance, and available hazard assessment, in order to have an updated picture of the state knowledge on volcanic hazard. We follow a prototypal reviewing scheme, based on three standardized steps: i) review of the volcanic system; ii) review of available eruptive and noneruptive hazard quantifications; iii) development of a conceptual interpretative model. We find that, while a rather vast literature is dedicated to the volcanic system of Vulcano and the reconstruction of past events, few quantitative hazard assessments exist. In addition, the range of natural variability considered for each hazard is potentially underestimated (e.g. limited range of considered eruption magnitude and style and of vent position), as it is the potential effect of multi-hazard impact. The developed conceptual model for the feeding system provides a synthetic picture of the present knowledge about the system, as emerged from the review. In addition, it allows for the identification of potential paths-to-eruption and provides a first order link among the main hazards. This review provides an up-to-date snapshot of existing knowledge on volcanic hazard at Vulcano on which to build future hazard quantifications as well as to support present and future decision making.
    Description: Published
    Description: 103186
    Description: 1V. Storia eruttiva
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Tephra dispersal and sedimentation (2020)
    Details
    Publication Date: 2021-05-17
    Description: NA
    Description: Published
    Description: 587-597
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Description: N/A or not JCR
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    The NEWTON-g Gravity Imager: Toward New Paradigms for Terrain Gravimetry (2021)
    Frontiers
    Details
    Publication Date: 2021-01-07
    Description: Knowledge of the spatio-temporal changes in the characteristics and distribution of subsurface fluids is key to properly addressing important societal issues, including: sustainable management of energy resources (e.g., hydrocarbons and geothermal energy), management of water resources, and assessment of hazard (e.g., volcanic eruptions). Gravimetry is highly attractive because it can detect changes in subsurface mass, thus providing a window into processes that involve deep fluids. However, high cost and operating features associated with current instrumentation seriously limits the practical field use of this geophysical method. The NEWTON-g project proposes a radical change of paradigm for gravimetry through the development of a fieldcompatible measuring system (the gravity imager), able to real-time monitor the evolution of the subsurface mass changes. This system includes an array of lowcosts microelectromechanical systems-based relative gravimeters, anchored on an absolute quantum gravimeter. It will provide imaging of gravity changes, associated with variations in subsurface fluid properties, with unparalleled spatio-temporal resolution. During the final ∼2 years of NEWTON-g, the gravity imager will be field tested in the summit of Mt. Etna volcano (Italy), where frequent gravity fluctuations, easy access to the active structures and the presence of a multiparameter monitoring system (including traditional gravimeters) ensure an excellent natural laboratory for testing the new tools. Insights from the gravity imager will be used to i) improve our knowledge of the causeeffect relationships between volcanic processes and gravity changes observable at the surface and ii) develop strategies to best incorporate the gravity data into hazards assessments and mitigation plans. A successful implementation of NEWTON-g will open new doors for geophysical exploration.
    Description: Published
    Description: 573396
    Description: 1IT. Reti di monitoraggio e sorveglianza
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    Integrative Post-event Impact Assessment Framework for Volcanic Eruptions: A Disaster Forensic Investigation of the 2011–2012 Eruption of the Cordón Caulle Volcano (Chile) (2021)
    Frontiers
    Details
    Publication Date: 2021-07-07
    Description: Understanding the complexity of future volcanic impacts that can be potentially induced by the large variability of volcanic hazards and the multiple dimensions of vulnerability of the increasingly interdependent and interconnected societies, requires an in-depth analysis of past events. A structured and inclusive post-event impact assessment framework is proposed and applied for the evaluation of damage and disruption on critical infrastructures caused by the eruption of the Cordón Caulle volcano (Chile) in 2011–2012. This framework is built on the forensic analysis of disasters combined with the techniques of the root cause analysis that converge in a bow-tie tool. It consists of a fault tree connected to subsequent event trees to describe the causal order of impacts. Considering the physical and systemic dimensions of vulnerability, four orders of impact have been identified: i) the first order refers to the physical damage or the primary impact on a component of the critical infrastructure; ii) the second order refers to the loss of functionality in the system due to a physical damage on key components of the system; iii) the third order refers to the systemic impact due to the interdependency and connectivity among different critical infrastructures; and iv) a higher order is related to the consequences on the main economic sectors and to social disruption that can activate an overall damage to the economy of the country or countries affected. Our study in the Argentinian Patagonia shows that the long-lasting impact of the 2011–2012 Cordón Caulle eruption is mostly due to a secondary hazard (i.e., wind remobilisation of ash), which exacerbated the primary impact affecting significantly larger areas and for longer time with respect to primary tephra deposition. In addition, systemic vulnerability, particularly the intrinsic dependencies within and among systems, played a major role in the cascading impact of the analysed communities.
    Description: This study was supported by the Swiss National Science Foundation (200021–163152).
    Description: Published
    Description: 645945
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Description: JCR Journal
    Keywords: impact assessment ; volcanic eruptions ; forensic analysis ; systemic vulnerability ; cascading effects ; bow-tie approach ; 04.08. Volcanology ; 05.08. Risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 6
    facet.materialart.
    Unknown
    Multisensor Characterization of the Incandescent Jet Region of Lava Fountain-Fed Tephra Plumes (2021)
    MDPI
    Details
    Publication Date: 2021-01-07
    Description: Explosive basaltic eruptions eject a great amount of pyroclastic material into the atmosphere, forming columns rising to several kilometers above the eruptive vent and causing significant disruption to both proximal and distal communities. Here, we analyze data, collected by an X-band polarimetric weather radar and an L-band Doppler fixed-pointing radar, as well as by a thermal infrared (TIR) camera, in relation to lava fountain-fed tephra plumes at the Etna volcano in Italy. We clearly identify a jet, mainly composed of lapilli and bombs mixed with hot gas in the first portion of these volcanic plumes and here called the incandescent jet region (IJR). At Etna and due to the TIR camera configuration, the IJR typically corresponds to the region that saturates thermal images. We find that the IJR is correlated to a unique signature in polarimetric radar data as it represents a zone with a relatively high reflectivity and a low copolar correlation coe cient. Analyzing five recent Etna eruptions occurring in 2013 and 2015, we propose a jet region radar retrieval algorithm (JR3A), based on a decision-tree combining polarimetric X-band observables with L-band radar constraints, aiming at the IJR height detection during the explosive eruptions. The height of the IJR does not exactly correspond to the height of the lava fountain due to a di erent altitude, potentially reached by lapilli and blocks detected by the X-band weather radar. Nonetheless, it can be used as a proxy of the lava fountain height in order to obtain a first approximation of the exit velocity of the mixture and, therefore, of the mass eruption rate. The comparisons between the JR3A estimates of IJR heights with the corresponding values recovered from TIR imagery, show a fairly good agreement with di erences of less than 20% in clear air conditions, whereas the di erence between JR3A estimates of IJR height values and those derived from L-band radar data only are greater than 40%. The advantage of using an X-band polarimetric weather radar in an early warning system is that it provides information in all weather conditions. As a matter of fact, we show that JR3A retrievals can also be obtained in cloudy conditions when the TIR camera data cannot be processed.
    Description: Published
    Description: 3629
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: JCR Journal
    Keywords: 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 7
    facet.materialart.
    Unknown
    Exposure-based risk assessment and emergency management associated with the fallout of large clasts at Mount Etna (2020)
    Details
    Publication Date: 2020-02-07
    Description: Fallout of ballistic blocks and bombs ejected from eruptive vents represents a well-known hazard in areas proximal to volcanoes (mostly 〈 5 km from the vent). However, fallout of large clasts sedimenting from plume margins that extend to medial areas and have the potential to produce severe injuries to people and cause damage to infrastructure, is often overlooked. Recent eruptive events at Mount Etna (Italy) provide a clear example where large-clast fallout from plume margins (〉5 cm) has posed a real threat both to the many visitors reaching the summit area and to local infrastructure, and, therefore, has been selected as a case study. To quantify this hazard, a new particle sedimentation model was calibrated with field data and then used for probabilistic hazard assessments. For a fully probabilistic scenario the hazard zone covered 72 km2 and included some 125 km of paths and roads, as well as 15 buildings. Evacuation on foot to a safe area was estimated at almost 4 h, but this could be reduced to less than 3 h if two shelters were provided. Our results show the importance of integrating probabilistic hazard analysis of large-clast fallout within effective strategies of risk management and reduction, especially in the case of volcanoes where visitors can reach the summit areas.
    Description: Published
    Description: 589–610
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    Tecolote volcano, Pinacate volcanic field (Sonora, Mexico): A case of highly explosive basaltic volcanism and shifting eruptive styles (2020)
    Details
    Publication Date: 2020-05-27
    Description: Explosive basaltic eruptions have been documented in monogenetic volcanic fields, and recognizing the scales of their explosivity is important for understanding the full range of basaltic volcanism. Here we reconstruct one of the youngest eruptions in the Pinacate volcanic field (Sonora, Mexico) and estimate the volumes of the lava flows, scoria cone, and tephra units. The source vent of the eruption is Tecolote volcano (27 ± 6 ka, 40Ar/39Ar). There were two distinct episodes of tephra production, Tephra Unit 1 (T1) followed by Tephra Unit 2 (T2). T1 and T2 show different dispersal patterns, with T1 dispersed in an approximately circular pattern and T2 dispersed oblately trending SE and NW of the vent. Based on column height reconstructions and deposit characteristics, the T1-producing eruption was subplinian (15–18 km plume), with a calculated mass eruption rate ranging between 1.0 ± 0.6 × 107 kg/s and 2.2 ± 1.2 × 107 kg/s and corresponding durations between 79 ± 54 min and 38 ± 26 min, respectively. The T2-producing eruption was violent Strombolian (11 km plume) with a calculated mass eruption rate of 3.2 ± 1.4 × 106 kg/s and resulting duration of 193 ± 78 min. In addition to the two tephra units, Tecolote volcano produced seven morphologically distinct lava flows. The majority of lava volume production occurred before—and partly contemporaneously with—tephra production, and five small-volume lava flows were emplaced after pyroclastic activity terminated, indicating shifting and simultaneous eruptive styles. Of the total 0.23 km3 dense rock equivalent (DRE) erupted volume, the lava flows constitute the majority (0.17 km3 DRE), with 0.041 km3 DRE volume for the cone and a combined 0.026 ± 0.005 km3 DRE volume for the two tephra units. The geochemistry of the samples is consistent with that determined for other Pinacate rocks, which show a trend most similar to that of ocean island basalts and appears characteristically similar to other volcanic fields of the Basin and Range province
    Description: Published
    Description: 23-44
    Description: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici
    Description: JCR Journal
    Keywords: Tephra deposit ; Pinacate volcanic field ; 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 9
    facet.materialart.
    Unknown
    A new way to reduce the impact from tephra fallout during Etna explosive eruptions (2019)
    Miscellanea INGV
    Details
    Publication Date: 2019-10-24
    Description: The frequent number of explosive events at Mt. Etna, in Italy, over the last ten years, has made necessary the improvement of volcanic ash monitoring and forecasting system at the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo (INGV-OE). Tephra fallout produced during Etna lava fountains largely impact the population living on the volcano flanks. In addition, during one of the most powerful paroxysms, large clasts fell in proximal areas injured tourists and hikers. To reduce risk, the Italian Department Civil Protection (DPC) asked and funded INGV-OE to do a research project finalized to three specific objectives. First, identify the plume scenario (i.e. weak plume scenario (WPS) and strong plume scenarios (SPS)) based on 1-D plume model. Second, forecast characteristics of tephra deposition using near real time observations. Third, identify the region possibly impacted by large clasts (〉5 cm). Two algorithms were developed to measure the column height. One from the calibrated images of two visible cameras installed on the S and W flanks of the volcano, respectively; and the other one from satellite data using a procedure based on the computation of the volcanic plume-top brightness temperature at 10.8 mm. The analysis of lava fountains that occurred between 2011 and 2015 provided the opportunity to differentiate between weak, transitional and strong plumes. The uncertainty associated with eruption source parameters, while maintaining a fixed plume height, was also assessed. In the near future the implementation of these products into the INGV-OE - monitoring room will guarantee a better and timely information to civil protection authorities charged of risk prevention at different levels of responsibility.
    Description: Published
    Description: Napoli
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Keywords: Etna ; tephra ; fallout ; explosive ; eruptions ; impact
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Conference paper
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 10
    facet.materialart.
    Unknown
    Estimating the volume of tephra deposits: A new simple strategy (2018)
    Details
    Publication Date: 2018-04-20
    Description: Volume determination of tephra deposits is necessary for the assessment of the dynamics and hazards of explosive volcanoes. Several methods have been proposed during the past 40 years that include the analysis of crystal concentration of large pumices, integrations of various thinning relationships, and the inversion of field observations using analytical and computational models. Regardless of their strong dependence on tephra-deposit exposure and distribution of isomass/isopach contours, empirical integrations of deposit thinning trends still represent the most widely adopted strategy due to their practical and fast application. The most recent methods involve the best fitting of thinning data using various exponential seg- ments or a power-law curve on semilog plots of thickness (or mass/area) versus square root of isopach area. The exponential method is mainly sensitive to the number and the choice of straight segments, whereas the power-law method can better reproduce the natural thinning of tephra deposits but is strongly sensitive to the proximal or distal extreme of integration. We analyze a large data set of tephra deposits and propose a new empirical method for the deter- mination of tephra-deposit volumes that is based on the integration of the Weibull function. The new method shows a better agreement with observed data, reconciling the debate on the use of the exponential versus power-law method. In fact, the Weibull best fitting only depends on three free parameters, can well reproduce the gradual thinning of tephra deposits, and does not depend on the choice of arbitrary segments or of arbitrary extremes of integration.
    Description: Published
    Description: 415-418
    Description: 5V. Dinamica dei processi eruttivi e post-eruttivi
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation 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...