Force‐Balance Analysis of Stress Changes During the Subduction‐Collision Transition and Implications for the Rise of Mountain Belts

Mountain height at convergent plate margins is limited by the megathrust shear force, but it remains unclear how this constraint affects topographic evolution and mountain building transition from subduction to collision. Generally, increases during subduction-collision in response crustal thickening or processes like mantle delamination slab breakoff, main parameters controlling much remain poorly understood. Here we show, based on analytical finite-element force-balance models, that increase depends magnitude of force reduction submarine margin relief. During stage, balanced gravitational effect relief deviatoric stresses upper are low. When reduced closure ocean basin, decreases experiences enhanced compression, which allows until a near-neutral stress state beneath high mountains restored. If cannot keep pace with reduction, compression few tens MPa, promotes tectonic shortening building. Our analysis implies can hundreds meters kilometers collision, depending primarily trench depth stage possible syncollisional changes force.