Deformation patterns associated with the seismic cycle of the 27 February Maule earthquake segment at various spatiotemporal scales

小组提案的总体目标已在摘要文件中加以说明。在俯冲-地震周期中应变的积累和释放控制着破坏性地震和相关海啸的复发和震级，如2010年Maule事件。了解地质地貌表现出的前地层长期变形模式与同震大逆冲滑动之间的关系，对于破解地震过程控制机制和评价地震危险性具有重要意义。在这项研究中，我们将获得详细的记录：(1)应变积累；(2)应变释放；(3)长期（103- 105年）的弧前变形，沿Maule断裂走向整合了几个地震旋回。有了这些定量信息，我们将解决正在进行的研究的基本问题，包括地震特征的时空维持；年代际尺度的潜在地震前兆信号；并利用海岸变形梯度预测特大逆冲滑动。我们的方法需要获得：(1)Maule事件之前整个震间期的陆地水平变化时间序列，作为应变积累的代理（大地测量、地貌和历史数据）；(2)通过浊积岩作为应变释放的代用物的沉积学和地质年代学分析，在百年至千年时间尺度上获得完整的古地震记录；(3)以海相阶地变形和流域形态计量指数为代表的沿海抬升速率，代表了几个地震周期积累的永久应变。

The overarching aims of the group proposal have been described in the summary document. Strain accumulation and release during the subduction-earthquake cycle governs the recurrence and magnitude of destructive earthquakes and associated tsunamis, such as the 2010 Maule event. Understanding the relation between long-term deformation patterns of forearcs manifested in the geology and geomorphology, and co-seismic megathrust slip is of utmost importance for deciphering the mechanisms governing the earthquake process and assessments of seismic hazards. In this study we will obtain detailed records of: (1) strain accumulation; (2) strain release; and (3) long-term (103- 105 yr) forearc deformation that integrates over several earthquake cycles, along strike of the Maule rupture. With this quantitative information, we will tackle fundamental problems of ongoing research, including the spatiotemporal sustenance of seismic asperities; potential earthquake precursory signals at decadal scale; and the use of coastal deformation gradients to predict megathrust slip. Our approach entails obtaining: (1) time series of land-level changes during the full inter-seismic period before the Maule event as a proxy for strain accumulation (geodetic, geomorphic and historical data); (2) a complete paleoseismic record at centennial to millennial time scales through a sedimentologic and geochronologic analysis of turbidites as proxy for strain release; and (3) coastal uplift rates deduced from deformed marine terraces and morphometric indices of drainage basins as proxy for permanent strain accumulated over several earthquake cycles.