A Visual Survey of Global Slab Geometries With ShowEarthModel and Implications for a Three‐Dimensional Subduction Paradigm

Abstract

Increasing volumes of digital data, combined with advances in visualization, allow for a new three‐dimensional (3D) conceptualization of modern subduction systems. Here we present 16 visual exploration sessions with the ShowEarthModel program that interrogate modern slab morphologies on Earth. These virtual voyages through the Earth's interior provide a snapshot into the four‐dimensional evolution of plate tectonics, captured by the modern state of slab structure. Examining the modern subduction system in an interactive 3‐D framework provides an improved conceptualization of the morphology of slabs. The movies demonstrate that unlike the modern mid‐ocean ridge system, modern subduction systems are laterally discontinuous features, making lateral slab edges prevalent. The 3‐D visualizations elucidate the manner in which slabs intersect and overlap, processes that occur in at least six of the Earth's major subduction zones. The observed variability within a given subduction zone as well as the physical presence of intersecting slabs suggests that slab gaps and slab windows are common. The 3‐D rendering shows relative differences in the radius of curvature for arcuate slabs, as well as the variability in dip within a given subduction zone. Addressing the complex geometries of subducted lithosphere in this way can place constraints on outstanding questions of subduction dynamics including slab strength, mantle rheology, mantle flow circulation, and plate‐asthenosphere coupling. By conceptualizing the modern subduction system on Earth in 3‐D space, this paper contributes to the paradigm shift from a two‐dimensional (2‐D) to 3‐D framework for interpreting the subduction process.

Mapping the Lithosphere and Asthenosphere Beneath Alaska With Sp Converted Waves

“…Estimates of active deformation are consistent with extension, given that the Seward Peninsula is pulling away to the southwest from northern Alaska; this extension is part of a regional pattern of surface velocities that includes the westward extrusion of southwestern Alaska (Elliott & Freymueller, 2020). Geodynamical modeling (e.g., Finzel et al., 2015; Jadamec & Billen, 2012; Jadamec et al., 2013, 2018) as well as mantle azimuthal anisotropy (e.g., McPherson et al., 2020; Venereau et al., 2019) indicate strongly three‐dimensional mantle flow associated with this surface deformation. Ongoing extension, potential upwelling within three‐dimensional asthenospheric flow and the partial melt it generates provide potential mechanisms for maintaining the thin lithosphere beneath the Seward Peninsula.…”

“…In the second region of high PVGm amplitude, which lies in eastern Alaska north of ∼63°N, Prindle volcano is the only Quaternary volcanic center (Figure 9a), and while its composition differs from the Alaskan arc and is more consistent with decompression melting, it still bears some signatures of subduction (Andronikov & Mukasa, 2010;Nye et al, 2018). The decompression here could be created by an upwelling component to asthenospheric flow that is circulating counter-clockwise around the edge of the subducting lithosphere (e.g., Jadamec & Billen, 2012;Jadamec et al, 2013Jadamec et al, , 2018, possibly in combination with flow through a slab tear (e.g., Fuis et al, 2008;Gou et al, 2019;Jiang et al, 2018). A melting front at ∼150 km depth that produces an observable PVGm can be created with only modest water content (<200 wt ppm) and mantle potential temperatures that overlap the range for ambient mantle as represented by mid-ocean ridges (Bao et al, 2022;Hua et al, 2021).…”

Regional crustal and lithospheric thickness model for Alaska, the Chukchi shelf, and the inner and outer bering shelves

“…(Eberhart-Phillips et al 2006, Fuis et al 2008Jadamec & Billen 2010). Farther west, the slab resumes a more typical slab dip (Jadamec et al 2018).…”

Data science for oceanography: from small data to big data

“…The University of California, Davis has realized in large-scale volume rendering, real-time illumination, multivariate feature extraction etc. (Jadamec, Kreylos, Chang, Fischer, & Yikilmaz, 2018;Yu, Xie, Ma, Kolla, & Chen, 2015). In addition, in terms of scientific visualization analysis, World Wind, Skyline, Open Scene Graph (OSG) and Google Earth can simulation and visualization of ocean and atmospheric environment (Sarthou, Mas, Jacquin, Moreno, & Salamon, 2015).…”