Dynamics of retreating slabs: 1. Insights from two-dimensional numerical experiments

F. Funiciello, G. Morra, Klaus Regenauer-Lieb, D. Giardini

    Research output: Contribution to journalArticle

    71 Citations (Scopus)

    Abstract

    We use two-dimensional numerical experiments to investigate the long-term dynamics of an oceanic slab. Two problems are addressed: one concerning the influence of rheology on slab dynamics, notably the role of elasticity, and the second dealing with the feedback of slab-mantle interaction to be resolved in part 2. The strategy of our approach is to formulate the simplest setup that allows us to separate the effects of slab rheology (part 1) from the effects of mantle flux (part 2). Therefore, in this paper, we apply forces to the slab using simple analytical functions related to buoyancy and viscous forces in order to isolate the role of rheology on slab dynamics. We analyze parameters for simplified elastic, viscous, and nonlinear viscoelastoplastic single-layer models of slabs and compare them with a stratified thermomechanical viscoelastoplastic slab embedded in a thermal solution. The near-surface behavior of slabs is summarized by assessing the amplitude and wavelength of forebulge uplift for each rheology. In the complete thermomechanical solutions, vastly contrasting styles of slab dynamics and force balance are observed at top and bottom bends. However, we find that slab subduction can be modeled using simplified rheologies characterized by a narrow range of selected benchmark parameters. The best fit linear viscosity ranges between 5 × 1022 Pa s and 5 × 1023 Pa s. The closeness of the numerical solution to nature can be characterized by a Deborah number >0.5, indicating that elasticity is an important ingredient in subduction.
    Original languageEnglish
    Pages (from-to)online - approx 5-20pp
    JournalJournal of Geophysical Research: Solid Earth
    Volume108
    Publication statusPublished - 2003

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    slabs
    Rheology
    slab
    Elasticity
    rheology
    experiment
    Experiments
    Buoyancy
    elasticity (mechanics)
    Viscosity
    Fluxes
    Feedback
    elasticity
    Wavelength
    Earth mantle
    subduction
    elastic properties
    mantle
    buoyancy
    ingredients

    Cite this

    @article{5749b2c8d506456aaefab16976bbabf5,
    title = "Dynamics of retreating slabs: 1. Insights from two-dimensional numerical experiments",
    abstract = "We use two-dimensional numerical experiments to investigate the long-term dynamics of an oceanic slab. Two problems are addressed: one concerning the influence of rheology on slab dynamics, notably the role of elasticity, and the second dealing with the feedback of slab-mantle interaction to be resolved in part 2. The strategy of our approach is to formulate the simplest setup that allows us to separate the effects of slab rheology (part 1) from the effects of mantle flux (part 2). Therefore, in this paper, we apply forces to the slab using simple analytical functions related to buoyancy and viscous forces in order to isolate the role of rheology on slab dynamics. We analyze parameters for simplified elastic, viscous, and nonlinear viscoelastoplastic single-layer models of slabs and compare them with a stratified thermomechanical viscoelastoplastic slab embedded in a thermal solution. The near-surface behavior of slabs is summarized by assessing the amplitude and wavelength of forebulge uplift for each rheology. In the complete thermomechanical solutions, vastly contrasting styles of slab dynamics and force balance are observed at top and bottom bends. However, we find that slab subduction can be modeled using simplified rheologies characterized by a narrow range of selected benchmark parameters. The best fit linear viscosity ranges between 5 × 1022 Pa s and 5 × 1023 Pa s. The closeness of the numerical solution to nature can be characterized by a Deborah number >0.5, indicating that elasticity is an important ingredient in subduction.",
    author = "F. Funiciello and G. Morra and Klaus Regenauer-Lieb and D. Giardini",
    year = "2003",
    language = "English",
    volume = "108",
    pages = "online -- approx 5--20pp",
    journal = "Journal of Geophysical Research - Oceans",
    issn = "0148-0227",
    publisher = "American Geophysical Union",

    }

    Dynamics of retreating slabs: 1. Insights from two-dimensional numerical experiments. / Funiciello, F.; Morra, G.; Regenauer-Lieb, Klaus; Giardini, D.

    In: Journal of Geophysical Research: Solid Earth , Vol. 108, 2003, p. online - approx 5-20pp.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Dynamics of retreating slabs: 1. Insights from two-dimensional numerical experiments

    AU - Funiciello, F.

    AU - Morra, G.

    AU - Regenauer-Lieb, Klaus

    AU - Giardini, D.

    PY - 2003

    Y1 - 2003

    N2 - We use two-dimensional numerical experiments to investigate the long-term dynamics of an oceanic slab. Two problems are addressed: one concerning the influence of rheology on slab dynamics, notably the role of elasticity, and the second dealing with the feedback of slab-mantle interaction to be resolved in part 2. The strategy of our approach is to formulate the simplest setup that allows us to separate the effects of slab rheology (part 1) from the effects of mantle flux (part 2). Therefore, in this paper, we apply forces to the slab using simple analytical functions related to buoyancy and viscous forces in order to isolate the role of rheology on slab dynamics. We analyze parameters for simplified elastic, viscous, and nonlinear viscoelastoplastic single-layer models of slabs and compare them with a stratified thermomechanical viscoelastoplastic slab embedded in a thermal solution. The near-surface behavior of slabs is summarized by assessing the amplitude and wavelength of forebulge uplift for each rheology. In the complete thermomechanical solutions, vastly contrasting styles of slab dynamics and force balance are observed at top and bottom bends. However, we find that slab subduction can be modeled using simplified rheologies characterized by a narrow range of selected benchmark parameters. The best fit linear viscosity ranges between 5 × 1022 Pa s and 5 × 1023 Pa s. The closeness of the numerical solution to nature can be characterized by a Deborah number >0.5, indicating that elasticity is an important ingredient in subduction.

    AB - We use two-dimensional numerical experiments to investigate the long-term dynamics of an oceanic slab. Two problems are addressed: one concerning the influence of rheology on slab dynamics, notably the role of elasticity, and the second dealing with the feedback of slab-mantle interaction to be resolved in part 2. The strategy of our approach is to formulate the simplest setup that allows us to separate the effects of slab rheology (part 1) from the effects of mantle flux (part 2). Therefore, in this paper, we apply forces to the slab using simple analytical functions related to buoyancy and viscous forces in order to isolate the role of rheology on slab dynamics. We analyze parameters for simplified elastic, viscous, and nonlinear viscoelastoplastic single-layer models of slabs and compare them with a stratified thermomechanical viscoelastoplastic slab embedded in a thermal solution. The near-surface behavior of slabs is summarized by assessing the amplitude and wavelength of forebulge uplift for each rheology. In the complete thermomechanical solutions, vastly contrasting styles of slab dynamics and force balance are observed at top and bottom bends. However, we find that slab subduction can be modeled using simplified rheologies characterized by a narrow range of selected benchmark parameters. The best fit linear viscosity ranges between 5 × 1022 Pa s and 5 × 1023 Pa s. The closeness of the numerical solution to nature can be characterized by a Deborah number >0.5, indicating that elasticity is an important ingredient in subduction.

    M3 - Article

    VL - 108

    SP - online - approx 5-20pp

    JO - Journal of Geophysical Research - Oceans

    JF - Journal of Geophysical Research - Oceans

    SN - 0148-0227

    ER -