Slip budgeT in subduction zones illuminated by geodetic measuRements and earthquake cycle defOrmation modelliNG – STRONG project

板块边界的累积应变（滑动平衡）决定了俯冲带大地震的位置和震级，经常引发破坏性的海啸。因此，滑动预算的调查和量化是最重要的，以提高地震和海啸灾害评估。在过去的几年中，丰富的地球物理和大地测量观测，以及巨大的努力，在正向和反向建模允许更好地调查滑动预算。尽管如此，它仍然是一个悬而未决的问题，在何种程度上震后滑动以及非线性粘弹性和多孔弹性松弛过程有助于所观察到的地表变形，余震的发生，和滑动预算估计。该项目旨在通过一个综合的工作流程来破译智利北方俯冲带中的这些研究问题，该工作流程集成了：1。在可变时空尺度上的卫星大地测量和地震活动数据，2。最先进的4D（空间和时间）地质力学正演模型，以及3.）一种倒置的方法。智利北方提供了一个独特的机会来研究地震周期相关的变形过程，因为智利综合板块边界（IPOC）的多参数仪器成功记录了2014年Mw 8.1伊基克地震之前，期间和之后的变形和地震活动。此外，智利北方相对较高的干旱导致干涉测量相干性高，非常适合以前所未有的分辨率检索干涉合成孔径雷达（干涉合成孔径雷达）数据。具体而言，该项目将侧重于处理和分析2014年伊基克地震后的新干涉合成孔径雷达数据。这些干涉合成孔径雷达数据将大大提高全球导航卫星系统（GNSS）数据的空间密度，从而将允许约束模型的结果，更好地考虑摩擦断层滑动，非线性粘性松弛，和孔隙弹性过程。有了这一定量信息和综合工作流程，本提案的目标是：量化和理解控制地震周期变形的过程的相对贡献，如震间锁定、震后滑动（后滑动）、非线性粘弹性和孔隙弹性松弛。2.）的情况。估算现今滑动预算的空间分布，这对计算未来地震的震级和位置至关重要。3.）第三章说明地震和抗震滑动占总预算的比例。4.）阐明孔隙压力变化对余震在空间和时间上的作用，特别是那些发生在地壳岸上的余震。

The accumulated strain at plate boundaries (slip budget) governs the location and magnitude of large earthquakes at subduction zones, often triggering destructive tsunamis. Hence, the investigation and quantification of slip budgets are of upmost importance to improve seismic and tsunami hazard assessment. During the last years, the wealth of geophysical and geodetic observations, as well as great effort in forward and inverse modelling have allowed a better investigation of slip budgets. Despite this, it is still an open question to what extent postseismic slip as well as non-linear viscoelastic and poroelastic relaxation processes contribute to the observed surface deformation, the occurrence of aftershocks, and the slip budget estimation. This project aims at deciphering these research questions in the northern Chile subduction zone using a comprehensive workflow that integrates: 1.) Satellite geodetic and seismicity data at variable spatiotemporal scales, 2.) a state-of-the-art 4D (space and time) geomechanical forward model, and 3.) an inversion approach. Northern Chile provides a unique opportunity to investigate earthquake cycle-related deformation processes as the deformation and seismicity before, during, and after the 2014 Mw 8.1 Iquique earthquake has been successfully recorded by the multi-parameter instrumentation of the Integrated Plate Boundary Chile (IPOC). Moreover, the relatively high aridity of northern Chile results in high interferometric coherence, ideal for retrieving Interferometric Synthetic-Aperture Radar (InSAR) data with an unprecedented resolution. Specifically, this project will focus on processing and analyzing new InSAR data following the 2014 Iquique earthquake. These InSAR data will substantially improve the spatial density of Global Navigation Satellite System (GNSS) data and thus will allow constraining the model results better considering frictional fault slip, non-linear viscous relaxation, and poroelastic processes. With this quantitative information and integrated workflow, this proposal aims at 1.) Quantifying and understanding the relative contribution of the processes controlling the deformation over the seismic cycle, such as interseismic locking, postseismic slip (afterslip), non-linear viscoelastic, and poroelastic relaxation. 2.) Estimation of the present-day spatial distribution of the slip budget, which is essential to calculate the magnitude and location of future earthquakes. 3.) Elucidating the ratio between seismic and aseismic slip to the total budget. 4.) Elucidating the role of pore-pressure changes on aftershocks in space and time, particularly those occurring on-shore in the crust.