Applications of the State-of-the-Art Seismic Analysis Methods to the Island of Hawaii

夏威夷是世界上地震最活跃的地区之一，在过去的几十年里一直是研究地震和岩浆作用之间相互作用的天然实验室。我们提出了一项为期两年的计划，将最先进的地震分析技术应用到夏威夷岛，利用波形互相关来评估精细的近震源空间和时间火山构造变化，并改善地震位置。拟议研究中使用的数据是来自美国地质勘探局夏威夷火山观测站和临时地震台站的大约15万次地震的数字地震数据。该应用程序的目标是整合夏威夷的地震数据，以更好地了解近源地震参数的性质。在拟议的研究中，我们将在整个夏威夷岛执行以下五项具体任务：(1)利用波形互相关计算纵波和横波的差异时间；(2)使用最新的层析算法将岩浆系统成像到复合事件数据集；(3)执行类似的事件集群分析和互相关重定位；(4)使用波形数据估计高分辨率的现场泊松比；以及(5)检查地震参数的时间变化。新开发的速度模型将用于确定管道和岩浆室，并改善绝对地震位置。高分辨率的现场泊松比将有助于追踪岩浆运动和估计部分熔体的比例。这些结果将更好地约束基于波形互相关数据的新的重新定位目录的地震位置。我们的结果将解决以下问题：(1)高分辨率三维(3D)速度模型的同时反演将揭示关于岩浆系统和可能的岩浆体的什么？(2)来自三维速度模型的绝对位置约束将告诉我们关于毛纳罗阿和基拉韦厄断裂带的什么？(3)根据波形互相关数据估计的高分辨率原位近源参数将揭示近源区的时空特征？(4)夏威夷的长期地震速度变化与其他地区相比如何？这项研究的结果将产生一个适用于地质、构造和火山学社区的公共信息数据库。

Hawaii is one of the most seismically active regions in the world and has been serving as a natural laboratory for studying the interactions between seismic and magmatic processes for the past few decades. We propose a two-year program to apply the state of the art seismic analysis techniques that take advantage of waveform cross-correlation to the Island of Hawaii to assess the fine-scale near-source spatial and temporal volcanic structural variations and to improve earthquake locations. The data to be used in the proposed research are the digital seismic data from the USGS Hawaiian Volcano Observatory and temporary seismic stations for about 150,000 earthquakes. The objective of this application is to integrate seismic data of Hawaii to better understand the nature of the near-source seismic parameters. In the proposed research, we will pursue the following five specific tasks to the entire Island of Hawaii: (1) to calculate both compressional and shear wave differential times by using waveform cross-correlation, (2) to image the magmatic system using the most recent tomography algorithm to a composite event data set, (3) to perform similar event cluster analysis and cross-correlation relocation, (4) to estimate high-resolution in situ Poisson's ratio using waveform data, and (5) to examine temporal variations in seismic parameters. The newly developed velocity models will be used to resolve conduits and magma chambers and to improve absolute earthquake locations. In situ Poisson's ratios with high-resolution will be of great help to track magma moving and estimate fraction of partial melt. These results will better constrain earthquake locations for a new relocation catalog based on waveform cross-correlation data. Our results will address the following questions: (1) what will the simultaneous inversions of the high-resolution three-dimensional (3-D) velocity models reveal about the magmatic system and possible magma bodies? (2) What will the absolute location constraints from 3-D velocity models tell us about the fault zones in Mauna Loa and Kilauea? (3) What will the high-resolution in situ near-source parameters estimated from waveform cross-correlation data reveal about the spatial and temporal characteristics in the near-source region? (4) How do the long-lasting seismic velocity variations in Hawaii compare to other regions? The results from this study will generate a public database of information suitable for the geology, tectonics, and volcanology communities.