Long- and short-term deformation of convergent plate margins: Numerical modelling of seismic cycles at the South-Chilean oblique subduction zone

纳斯卡板块在南安第斯山脉下的俯冲导致了几次历史上的破坏性地震。这些地震似乎在周期中重新发生，与斜俯冲方向一起，影响智利前弧和弧在不同时间尺度上的活动变形。虽然构造变形对灾害评估非常重要，但对上板块的短期和长期变形之间的关系还没有很好的了解。短期变形与地震和随后几十年释放的瞬时弹性和粘性应力有关。长期变形，相反，表现为永久性的结构，如走滑断层在火山弧，可容纳向北迁移的弧前银，以及盆地和半岛的弧前。这是一项建议，开发数字模型，将自我运行的重复地震（地震周期）和板块边缘的神学不均匀性，目的是更好地了解安第斯地壳变形的长期和短期尺度。我们将研究（a）斜向会聚引起的弧前迁移和断层再活化，以及（B）可能导致弧前盆地和半岛的逆冲界面处物质的增加和去除。这些过程应结合起来并与GPS、重力、地震和地质数据进行比较。本研究的深远目标是更好地识别斜向俯冲逆冲界面的耦合特征，并测试地震的时间、大小和位置如何与短期和长期地壳变形相联系。

The subduction of the Nazca plate beneath the Southern Andes has resulted in several destructive historical earthquakes. These earthquakes appear to re-occur in cycles which, together with the oblique subduction direction, influence active deformation in the Chilean forearc and arc on different time scales. Although tectonic deformation is of high importance for hazard assessment, the relationship between the short-term and the long-term deformation of the upper plate is not well understood. The short-term deformation is related to transient elastic and viscous stresses that are released at earthquakes and the following decades. The long-term deformation, in contrast, is exhibited by permanent structures such as a strike-slip fault in the volcanic arc that accommodates northward migration of a forearc sliver, as well as basins and peninsulas in the forearc. This is a proposal to develop numerical models that incorporate self-running repeated earthquakes (seismic cycles) and the Theological heterogeneities of the plate margin with the goal to better understand the Andean crustal deformation on long- and short-term scales. We will investigate (a) the migration of the forearc and fault reactivation arising from oblique convergence, and (b) the addition and removal of material at the thrust interface that may be responsible for forearc basin and peninsula. These processes shall be combined and compared to GPS, gravimetric, seismic and geological data. The far-reaching goal of this study is to better identify the characteristics of the coupling at an oblique subduction thrust interface, and to test how the timing, size and location of earthquakes are linked to the short-term and the long-term crustal deformation.