09:00 〜 09:15
[SIT17-01] Compaction pressure goes global: Investigating fluid release and flow in subduction zones worldwide
★Invited Papers
Subduction of oceanic slabs causes the influx of fluids through hydrated phases. Fluids are released by metamorphic dehydration reactions particularly when the slab gets in contact with the hot mantle wedge at depths greater than ~80 km. Fluid release and subsequent flow can be diverse and occur at different depths inside the oceanic slab with sediments and uppermost oceanic crust generally dehydrating before the serpentinized mantle and gabbroic sections.
Significant progress has been made in recent years on geophysical imaging of subduction zones that highlight the thermal structure, the location of metamorphic dehydration reactions, and the presence of fluids in slab and mantle wedge (e.g., Kita et al., Tectonophysics, 2010; van Keken et al., Solid Earth, 2012; Shiina et al., GRL, 2013; Pommier and Evans, Geosphere, 2017). In a complimentary fashion, geodynamical modeling provides first principals constraints on how fluids are released and transported.
Using a simplified modeling geometry, Wilson et al. (EPSL, 2014) showed the importance of compaction pressure as an oft-cited, but also frequently ignored, driving force for fluids in the slab. The inclusion of compaction pressure causes the fluids to both be driven from their source to the arc and flow up in part parallel to the slab surface, explaining to at least some extent geophysical observations.
In this presentation we will review recent progress in geophysical imaging and provide a new global set of fluid flow models that take into account compaction pressure and the broad diversity of subduction zone geometry & thermal structure along with the modest control of rheologically controlled shear heating along the shallow plate interface (Abers et al., Geosphere, 2020).
Significant progress has been made in recent years on geophysical imaging of subduction zones that highlight the thermal structure, the location of metamorphic dehydration reactions, and the presence of fluids in slab and mantle wedge (e.g., Kita et al., Tectonophysics, 2010; van Keken et al., Solid Earth, 2012; Shiina et al., GRL, 2013; Pommier and Evans, Geosphere, 2017). In a complimentary fashion, geodynamical modeling provides first principals constraints on how fluids are released and transported.
Using a simplified modeling geometry, Wilson et al. (EPSL, 2014) showed the importance of compaction pressure as an oft-cited, but also frequently ignored, driving force for fluids in the slab. The inclusion of compaction pressure causes the fluids to both be driven from their source to the arc and flow up in part parallel to the slab surface, explaining to at least some extent geophysical observations.
In this presentation we will review recent progress in geophysical imaging and provide a new global set of fluid flow models that take into account compaction pressure and the broad diversity of subduction zone geometry & thermal structure along with the modest control of rheologically controlled shear heating along the shallow plate interface (Abers et al., Geosphere, 2020).