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

纳斯卡板块俯冲到南安第斯山脉之下，导致了几次破坏性的历史地震。这些地震似乎以不同的时间尺度重复发生，与斜俯冲方向一起影响智利弧前和弧内的活动形变。尽管构造变形对灾害评估具有重要意义，但对上板块短期变形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。相反，长期的变形表现为永久性结构，如火山弧中的走滑断层，它容纳了弧前银条的向北迁移，以及弧前的盆地和半岛。这是一项关于开发数值模型的建议，其中纳入了自发性重复地震(地震周期)和板块边缘的神学不均一性，目的是在长期和短期尺度上更好地了解安第斯地壳形变。我们将研究(A)弧前的迁移和斜向会聚引起的断层重新激活，以及(B)可能导致弧前盆地和半岛的逆冲界面物质的添加和移除。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。这项研究的深远目标是更好地确定斜俯冲推覆界面上的耦合特征，并测试地震的时间、大小和位置与地壳短期和长期形变之间的联系。

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.