Massive Relocation of Earthquakes Recorded at Regional and Teleseismic Distances Using a Double-Difference Algorithm, with Application to Subduction Zones

高分辨率震源位置对于估计地震危险性、推断地球结构、研究构造以及从根本上了解地震的发生和物理性质是至关重要的。最近的几项研究表明，通过将最近开发的双差（DD）地震定位算法应用于在局部距离记录的数千次浅层地震，可以大大改善地震位置。该项目侧重于调整DD方法，以便在大规模（数万次）和远距离（数千公里）上重新定位区域和远震距离记录的地震。调查人员将使用已知地面真相的全球记录事件来测试和评估新工具的性能，并将结果与常用定位技术得出的结果进行比较。他们还将把DD方法应用到“整理”的ISC公报中，重新定位俯冲带的大量地震，目的是成像与下降板块相关的地震活动性的内部结构。最初的重点将放在安第斯俯冲带上，目的是详细定义板块的形态及其与微震活动模式和破坏性地震破裂区域的关系。他们还将重新安置其他地震活动密集的地区，以寻找时间和空间上的特征地震活动模式，这可能为瓦达蒂贝尼奥夫地震的发生和物理提供新的见解。

EAR-0229832Felix WaldhauserHigh-resolution hypocenter locations are most crucial in estimating seismichazard, inferring Earth structure, studying tectonics, and to the fundamentalunderstanding of the occurrence and physics of earthquakes. Several recentstudies, of which this is a continuation, have demonstrated the substantialimprovement in earthquake locations by applying a recently developeddouble-difference (DD) earthquake relocation algorithm to thousands of shallowearthquakes recorded at local distances. This project focuses on adapting the DD method to relocate, on a massive scale (several tens of thousands of events) and over large distances (thousands of km), earthquakes recorded at regional andteleseismic distances. The investigators will test and evaluate the performance of the new tools using globally recorded events for which ground truth is known, andcompare the results with results derived from commonly used location techniques.They will also apply the DD method to the 'groomed' ISC bulletin to relocate large numbers of earthquakes in subduction zones with the aim to image the internalstructure of seismicity associated with descending slabs. The focus willinitially be on the Andean subduction zone with the aim to define in detail themorphology of the slab and its correlation with patterns of microseismicity andthe rupture areas of damaging earthquakes. they will also relocate other areaswith dense seismicity to search for characteristic seismicity patterns in timeand space which may provide new insights into the occurrence and physics ofWadati Benioff earthquakes.