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

该小组提案的总体目标已在摘要文件中作了说明。俯冲地震周期中的应变积累和释放决定了破坏性地震和相关海啸的复发和强度，例如2010年的Maule事件。了解反映在地质地貌中的前弧长期变形模式与同震巨型逆冲断层滑动之间的关系，对于解释控制地震过程的机制和评估地震危险性至关重要。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）弧前变形，集成了几个地震周期，沿着走向的Maule破裂。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，包括地震粗糙体的时空维持;潜在的地震前兆信号在十年尺度;和使用海岸变形梯度来预测巨型逆冲断层滑动。我们的方法需要获得：（1）在Maule事件之前的整个地震间隔期间，陆地水平变化的时间序列作为应变积累的代理（2）通过浊积岩的沉积学和地质年代学分析，作为应变释放的代用指标，获得百年至千年时间尺度的完整古地震记录;（3）由变形的海洋阶地和流域形态指标推断的海岸抬升速率，作为几个地震循环累积的永久应变的替代。

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.