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
    facet.materialart.
    Unknown
    Buoyancy Versus Local Stress Field Control on the Velocity of Magma Propagation: Insight From Analog and Numerical Modelling (2023)
    Frontiers Media S.A.
    Details
    Publication Date: 2023-03-06
    Description: Magmatic dykes interact with heterogeneous crustal stress. As a result, their propagation towards the surface can be tortuous and their propagation velocity may vary. While the deflection of dykes in response to the local stress field has been addressed by several studies, less has been done about the effect on their propagation velocity. Understanding under which conditions an intrusion may accelerate or decelerate due to crustal stress heterogeneities has obvious important implications in terms of forecasting the timing of the onset of the eruption. Here we analyse the velocity of fluid-filled crack propagation in a gelatin block characterized by a heterogenous stress field considering the case study of a load applied at the surface. We find that a crack deflected towards the load and its underlying compressive stress field is decelerated. By comparing experimental results with numerical solutions, we evidence the potential complementary role played by stress field variations and changes in trajectory orientation, controling the buoyancy, on the velocity of magma propagation. We also show that the energy release estimated along the crack path by simplified numerical models appears to be a good proxy for the velocity. We conclude that numerical models allowing for magma path estimations could also be used to infer magma velocity variations. In addition, 1D numerical models solving for the fluid flow along a prescribed path, provide velocity variation as a function of the surrounding stress field and the magma driving pressure.
    Description: Published
    Description: 838318
    Description: 4V. Processi pre-eruttivi
    Description: JCR Journal
    Keywords: magma propagation, analog experiments, numerical modelling, volcanic hazard, hydraulic fracture ; 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    Modeling the Shape and Velocity of Magmatic Intrusions, a New Numerical Approach (2023)
    Wiley-AGU
    Details
    Publication Date: 2023-04-17
    Description: Dykes are magma-filled fractures propagating through the brittle crust. Understanding the physics of dyking process is essential to mitigate the volcanic hazard associated with the opening of new eruptive fissures at the surface. Often, physics-based models view either fracturing of the host rock or viscous flow of the magma as the dominating energy sink during dyke propagation. Here, we provide a numerical model that captures the coupling of fracturing at the crack tip and the transport of a viscous fluid. Built with the boundary element technique, our model allows for computation of the shape and velocity of a growing fluid-filled crack accounting for the viscosity of the fluid: the fluid flow induces a viscous pressure drop acting at the crack walls, and modifies the shape of the crack. The energy conservation equation provides the constraints to solve for the crack growth velocity, assuming that brittle fracturing and viscous flow are the main processes that dissipate energy. Using a parameter range that represents typical magmatic intrusions, we obtain crack shapes displaying some typical characteristics, including a tear-drop head and an open tail that depend on rock rigidity, magma viscosity, and buoyancy. We show that viscous forces significantly contribute to the energy dissipated during the propagation of magmatic dykes. Applied to the 1998 intrusion at Piton de la Fournaise (La Réunion Island), we provide ranges of dyke lengths and openings by adjusting the numerical velocity to the one deduced from the migration of volcano-tectonic events.
    Description: Published
    Description: e2022JB025697
    Description: 2V. Struttura e sistema di alimentazione dei vulcani
    Description: 4V. Processi pre-eruttivi
    Description: JCR Journal
    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
    Dynamics of magmatic intrusion: what can we learn from the comparison of analog and numerical models? (2024)
    Presses universitaires de Strasbourg
    Details
    Publication Date: 2024-02-27
    Description: This study investigates the dynamics of magmatic intrusions based on the joint analysis of analog and numerical models.By injecting different fluids from the bottom of a solidified gelatin block, we simulate the propagation of magmatic intrusions through the crust and record their shapes, trajectories, and velocity as they rise towards the surface. Additionally, we make use of a 2D fluid-filled crack propagation model constrained by our experimental observations. The numerical simulations demonstrate that our viscous fluid-filled crack experiments, conducted with silicon-oil injections, propagate in the same regime as typical basaltic intrusions. The comparison between analog and numerical results allow us to define the domain of validity of the numerical model and its limit of applicability. This study provides new insights into the processes that control the propagation of magmatic intrusions and our ability to reproduce them using analog and numerical models.
    Description: Published
    Description: 67-87
    Description: OSV1: Verso la previsione dei fenomeni vulcanici pericolosi
    Description: N/A or not JCR
    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
    Lithosphere rigidity by adjoint-based inversion of interseismic GPS data, application to the Western United States (2018)
    Elsevier
    Details
    Publication Date: 2018-10-01
    Description: While vertical motion induced by long-term geological loads is often used to estimate the flexural rigidity of the lithosphere, we intend to evaluate the shear rigidity of the lithosphere using horizontal motion. Our approach considers that the rigidity of the lithosphere may be defined as its resistance to horizontal tectonic lateral forces. In this case, a spatial distribution of an effective shear rigidity can be estimated from the analysis of the interseismic velocity fields. We consider the Western United States zone where weakly strained areas (e.g., the Sierra Nevada) are connected with areas of large strain rate (e.g. San Andreas Fault system). By inverting interseismic strain distribution measured by geodetic methods, we infer the effective shear rigidity of the lithosphere. The forward problem is defined using the equations of linear elasticity. The inversion relies on the minimization of the sum of a quadratic measure of the differences between measured and modelled velocity fields. The functional also includes regularization terms for the parameters of the model. The gradient of the functional with respect to the minimization parameters is computed using an adjoint formulation. This permits the treatment of large dimensional minimization problems. Finally, a measure of the uncertainty of our inversion is illustrated through the covariance matrix of the parameters at the optimum. The optimization chart is validated on two synthetic velocity distributions. Then, the effective shear rigidity variations of the Western United States are estimated using the CMM3 interseismic velocities. The inversion displays low effective rigidities along the San Andreas Fault system, the Mojave Desert and in the Eastern California Shear Zone, while rigid areas are found in the Sierra Nevada and in the South Basin and Range. Finally, we discuss the differences between our strain rate and rigidity maps with previously published results for the Western United States.
    Print ISSN: 0040-1951
    Electronic ISSN: 1879-3266
    Topics: Geosciences , Physics
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Modeling the shape and velocity of magmatic intrusions, a new numerical approach (2023)
    Wiley | AGU
    Details
    Publication Date: 2024-02-07
    Description: Dykes are magma-filled fractures propagating through the brittle crust. Understanding the physics of dyking process is essential to mitigate the volcanic hazard associated with the opening of new eruptive fissures at the surface. Often, physics-based models view either fracturing of the host rock or viscous flow of the magma as the dominating energy sink during dyke propagation. Here, we provide a numerical model that captures the coupling of fracturing at the crack tip and the transport of a viscous fluid. Built with the boundary element technique, our model allows for computation of the shape and velocity of a growing fluid-filled crack accounting for the viscosity of the fluid: The fluid flow induces a viscous pressure drop acting at the crack walls, and modifies the shape of the crack. The energy conservation equation provides the constraints to solve for the crack growth velocity, assuming that brittle fracturing and viscous flow are the main processes that dissipate energy. Using a parameter range that represents typical magmatic intrusions, we obtain crack shapes displaying some typical characteristics, including a tear-drop head and an open tail that depend on rock rigidity, magma viscosity and buoyancy. We show that viscous forces significantly contribute to the energy dissipated during the propagation of magmatic dykes. Applied to the 1998 intrusion at Piton de la Fournaise (La Réunion Island), we provide ranges of dyke lengths and openings by adjusting the numerical velocity to the one deduced from the migration of volcano-tectonic events. Key Points We present a new modeling scheme to compute the shape and velocity of a growing fluid-filled crack Our magmatic dykes show a tear drop head and open tail, on a wide range of propagation velocities We reproduce the velocity and fit important parameters for the 1998 Piton de la Fournaise intrusion
    Type: Article , PeerReviewed
    Format: text
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 6
    facet.materialart.
    Unknown
    The PRE-COLLAPSE project: A holistic, shoreline-crossing approach to identify precursory signals of flank collapse at coastal and ocean island volcanoes (2022)
    Details
    Publication Date: 2024-02-19
    Type: Conference or Workshop Item , NonPeerReviewed
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 7
    facet.materialart.
    Unknown
    Dynamics of magmatic intrusion: what can we learn from the comparison of analog and numerical models? (2024)
    Presse universitaires de Strasbourg
    Details
    Publication Date: 2024-03-11
    Description: This study investigates the dynamics of magmatic intrusions based on the joint analysis of analog and numerical models. By injecting different fluids from the bottom of a solidified gelatin block, we simulate the propagation of magmatic intrusions through the crust and record their shapes, trajectories, and velocity as they rise towards the surface. Additionally, we make use of a 2D fluid-filled crack propagation model constrained by our experimental observations. The numerical simulations demonstrate that our viscous fluid-filled crack experiments, conducted with silicon-oil injections, propagate in the same regime as typical basaltic intrusions. The comparison between analog and numerical results allow us to define the domain of validity of the numerical model and its limit of applicability. This study provides new insights into the processes that control the propagation of magmatic intrusions and our ability to reproduce them using analog and numerical models.
    Type: Article , PeerReviewed
    Format: text
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 8
    facet.materialart.
    Unknown
    Are eruptions reliable precursors to marine volcano collapses? (2023)
    Frontiers
    Details
    Publication Date: 2024-03-20
    Description: Volcanoes are sources of numerous threats including lava flows, pyroclastic flows, ash dispersal and landslides or sector collapses. In addition to these commonly known volcanic hazards, volcano-induced tsunamis can occur in the marine environment, introducing a major hazard that can affect populations located far away from the volcanoes. Existing tsunami warning systems generally do not account for volcano-generated tsunamis, due to the multiple source mechanisms that can cause such tsunamis, a limited understanding of precursory signals for these events, and the need for local detection rather than remote sensing. Among these source mechanisms of volcanic tsunamis, sector and lateral collapses are at the high risk-low frequency extreme of risk matrices. Marine volcanoes grow in specific environments, with factors like marine clays, constant full saturation, sediment transport and remobilization, interaction with ocean dynamics, and sea level changes that may impact edifice stability in distinct ways. The majority of historically documented marine volcano collapses occurred at erupting volcanoes, suggesting that eruptions could serve as a remotely detectable warning signal for collapses. However, careful examination of temporal sequences of these examples reveals that collapses do not always follow eruptions. Consequently, there is a need for identifying other, more robust precursors to volcano collapse, in particular in the marine environment, where the consequences of collapses may be widespread.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...