Tectonic and geomorphological evolution of forearcs during ridge subduction

海底洋脊的俯冲造成上板块的相当大的隆起和变形，并可能导致离岸的前弧凹陷和陆上的不同模式的断层的发展，海洋阶地的形成和河流在俯冲脊以上的偏转。根据海脊相对于板块会聚方向的方位，海脊可能是静止的，也可能沿边缘沿着移动，造成弧前隆起和随后的沉降波。在这里，我们建议使用三维数值模式来调查的构造和地形演化的前弧脊俯冲的影响。使用不同的模型设置，我们将区分增生/侵蚀边缘和迁移/非迁移的山脊，分别。我们将改变脊的形状和前弧和板界面的机械强度，以确定最有影响力的参数。将针对脊引起的前弧几何形状、位移和应力场的变化对结果进行分析。为了研究脊俯冲对弧前地貌演化的影响，构造模型将与景观演化模型相结合。模拟的景观将揭示俯冲脊是否可能导致海岸附近河流的偏转。我们将把我们的研究结果与纳斯卡海脊（沿沿着侵蚀的秘鲁边缘迁移）、科科斯海脊（在侵蚀的中美洲边缘下静止俯冲）和加瓜海脊（沿沿着增生的琉球岛弧迁移）的碰撞区进行比较。

Subduction of submarine ridges causes considerable uplift and deformation of the upper plate and may lead offshore to the indentation of the forearc and onshore to the development of distinct patterns of faulting, the formation of marine terraces and the deflection of rivers above the subducting ridge. Depending on the orientation of the ridge relative to the plate convergence direction, the ridge may either be stationary or migrate along the margin, causing a wave of forearc uplift and subsequent subsidence. Here we propose to use 3D numerical models to investigate the tectonic and topographic evolution of forearcs affected by ridge subduction. Using different model setups we will distinguish between accretive/erosive margins and migrating/non-migrating ridges, respectively. We will vary the ridge shape and the mechanical strength of the forearc and the plate interface to identify the most influential parameters. The results will be analysed with respect to the ridge-induced changes of the forearc geometry, displacement and stress field. To investigate the impact of ridge subduction on the geomorphological evolution of the forearc, the tectonic models will be coupled to a landscape evolution model. The modelled landscapes will reveal if a subducting ridge may lead onshore to the deflection of rivers near the coast. We will compare our findings with the collision zones of the Nazca Ridge (migrating along the erosive Peruvian margin), the Cocos Ridge (subducting stationary beneath the erosive Central American margin) and the Gagua Ridge (migrating along the accretive Ryukyu island arc).