Matches in SemOpenAlex for { <https://semopenalex.org/work/W3113020610> ?p ?o ?g. }
- W3113020610 endingPage "2357" @default.
- W3113020610 startingPage "2327" @default.
- W3113020610 abstract "Abstract. Many plate tectonic processes, such as subduction initiation, are embedded in long-term (>100 Myr) geodynamic cycles often involving subsequent phases of extension, cooling without plate deformation and convergence. However, the impact of upper mantle convection on lithosphere dynamics during such long-term cycles is still poorly understood. We have designed two-dimensional upper-mantle-scale (down to a depth of 660 km) thermo-mechanical numerical models of coupled lithosphere–mantle deformation. We consider visco–elasto–plastic deformation including a combination of diffusion, dislocation and Peierls creep law mechanisms. Mantle densities are calculated from petrological phase diagrams (Perple_X) for a Hawaiian pyrolite. Our models exhibit realistic Rayleigh numbers between 106 and 107, and the model temperature, density and viscosity structures agree with geological and geophysical data and observations. We tested the impact of the viscosity structure in the asthenosphere on upper mantle convection and lithosphere dynamics. We also compare models in which mantle convection is explicitly modelled with models in which convection is parameterized by Nusselt number scaling of the mantle thermal conductivity. Further, we quantified the plate driving forces necessary for subduction initiation in 2D thermo-mechanical models of coupled lithosphere–mantle deformation. Our model generates a 120 Myr long geodynamic cycle of subsequent extension (30 Myr), cooling (70 Myr) and convergence (20 Myr) coupled to upper mantle convection in a single and continuous simulation. Fundamental features such as the formation of hyperextended margins, upper mantle convective flow and subduction initiation are captured by the simulations presented here. Compared to a strong asthenosphere, a weak asthenosphere leads to the following differences: smaller value of plate driving forces necessary for subduction initiation (15 TN m−1 instead of 22 TN m−1) and locally larger suction forces. The latter assists in establishing single-slab subduction rather than double-slab subduction. Subduction initiation is horizontally forced, occurs at the transition from the exhumed mantle to the hyperextended passive margin and is caused by thermal softening. Spontaneous subduction initiation due to negative buoyancy of the 400 km wide, cooled, exhumed mantle is not observed after 100 Myr in model history. Our models indicate that long-term lithosphere dynamics can be strongly impacted by sub-lithosphere dynamics. The first-order processes in the simulated geodynamic cycle are applicable to orogenies that resulted from the opening and closure of embryonic oceans bounded by magma-poor hyperextended rifted margins, which might have been the case for the Alpine orogeny." @default.
- W3113020610 created "2020-12-21" @default.
- W3113020610 creator A5019021930 @default.
- W3113020610 creator A5043182140 @default.
- W3113020610 creator A5083402854 @default.
- W3113020610 date "2020-12-07" @default.
- W3113020610 modified "2023-09-25" @default.
- W3113020610 title "Impact of upper mantle convection on lithosphere hyperextension and subsequent horizontally forced subduction initiation" @default.
- W3113020610 cites W1236722768 @default.
- W3113020610 cites W1493790006 @default.
- W3113020610 cites W1543257786 @default.
- W3113020610 cites W1564288678 @default.
- W3113020610 cites W1568261896 @default.
- W3113020610 cites W1590119439 @default.
- W3113020610 cites W1594412726 @default.
- W3113020610 cites W1971374046 @default.
- W3113020610 cites W1971450949 @default.
- W3113020610 cites W1973343024 @default.
- W3113020610 cites W1975017135 @default.
- W3113020610 cites W1975258099 @default.
- W3113020610 cites W1977212386 @default.
- W3113020610 cites W1978000377 @default.
- W3113020610 cites W1978320327 @default.
- W3113020610 cites W1981165981 @default.
- W3113020610 cites W1994583512 @default.
- W3113020610 cites W1996650279 @default.
- W3113020610 cites W1998781690 @default.
- W3113020610 cites W2003286675 @default.
- W3113020610 cites W2008338511 @default.
- W3113020610 cites W2011607179 @default.
- W3113020610 cites W2019010208 @default.
- W3113020610 cites W2021889619 @default.
- W3113020610 cites W2024447342 @default.
- W3113020610 cites W2025244602 @default.
- W3113020610 cites W2032149561 @default.
- W3113020610 cites W2032410808 @default.
- W3113020610 cites W2038325228 @default.
- W3113020610 cites W2038920423 @default.
- W3113020610 cites W2042806383 @default.
- W3113020610 cites W2046640225 @default.
- W3113020610 cites W2048742589 @default.
- W3113020610 cites W2052508457 @default.
- W3113020610 cites W2053747921 @default.
- W3113020610 cites W2056058082 @default.
- W3113020610 cites W2062221814 @default.
- W3113020610 cites W2062692849 @default.
- W3113020610 cites W2066887120 @default.
- W3113020610 cites W2070384913 @default.
- W3113020610 cites W2073132126 @default.
- W3113020610 cites W2076956561 @default.
- W3113020610 cites W2097914838 @default.
- W3113020610 cites W2098031509 @default.
- W3113020610 cites W2099949247 @default.
- W3113020610 cites W2100486566 @default.
- W3113020610 cites W2103386402 @default.
- W3113020610 cites W2112769507 @default.
- W3113020610 cites W2118622299 @default.
- W3113020610 cites W2118755672 @default.
- W3113020610 cites W2129333755 @default.
- W3113020610 cites W2132661748 @default.
- W3113020610 cites W2136594983 @default.
- W3113020610 cites W2139480736 @default.
- W3113020610 cites W2140202552 @default.
- W3113020610 cites W2145901303 @default.
- W3113020610 cites W2154134823 @default.
- W3113020610 cites W2163461684 @default.
- W3113020610 cites W2164161380 @default.
- W3113020610 cites W2170219059 @default.
- W3113020610 cites W2170479468 @default.
- W3113020610 cites W2170557875 @default.
- W3113020610 cites W2237873856 @default.
- W3113020610 cites W2296401513 @default.
- W3113020610 cites W2331677203 @default.
- W3113020610 cites W2340659542 @default.
- W3113020610 cites W2438061131 @default.
- W3113020610 cites W2525934248 @default.
- W3113020610 cites W2560220778 @default.
- W3113020610 cites W2569793001 @default.
- W3113020610 cites W2575647349 @default.
- W3113020610 cites W2608378763 @default.
- W3113020610 cites W2614268999 @default.
- W3113020610 cites W2761657324 @default.
- W3113020610 cites W2765248296 @default.
- W3113020610 cites W2789097411 @default.
- W3113020610 cites W2794214214 @default.
- W3113020610 cites W2795112298 @default.
- W3113020610 cites W2801769550 @default.
- W3113020610 cites W2804067255 @default.
- W3113020610 cites W2811196043 @default.
- W3113020610 cites W2887129899 @default.
- W3113020610 cites W2898545413 @default.
- W3113020610 cites W2899204758 @default.
- W3113020610 cites W2901015259 @default.
- W3113020610 cites W2901582080 @default.
- W3113020610 cites W2916097877 @default.
- W3113020610 cites W2946361099 @default.
- W3113020610 cites W2948953774 @default.
- W3113020610 cites W2963313004 @default.