Automated identification and timing of crustal phases for tomographic studies and applications to the Marmara region in NW Turkey

自动识别和计时地壳相，用于土耳其西北部马尔马拉地区的层析研究和应用

• 批准号: 215934311
• 负责人: Professor Dr. Marco Bohnhoff
• 金额: --
• 依托单位: Sektion 4.2: Geomechanik und Wissenschaftliches Bohren
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/215934311?language=en
• 关键词: Automated; identification; timing; crustal; phases

Precise knowledge of the 3D-velocity structure is an important pre-requisite when aiming at tectonically characterizing target regions using high-precision earthquake hypocenter locations. In that respect, precise phase arrival times selected from extensive waveform data archives are the most important input parameter. The aim of this project is to develop algorithms for automated identification and accurate timing of crustal phases and their inversion to derive a three-dimensional velocity model of the broader Marmara region in NW Turkey. Based on recent developments of automated P- and S-phase picking algorithms it is planned to extend and apply these algorithms to additional crustal and uppermost mantle phases such as Pg, Pn, PmP, and its S-wave pendants. Based on recent results, we will make use of statistical modeling, multivariate time series analysis, and heuristic methodologies. The new approach should also provide reliable, non-discrete and non-symmetrical error estimates of the derived phase-onset times. Arrival times of distinct identified phase onsets will serve as input for non-linear location methods like NonLinLoc and VELEST to establish a minimum 1D-velocity model, which will then serve as a starting model for the 3D-inversion using SIMULPS14. The newly developed algorithms will be applied to local and regional earthquake recordings from the Marmara region in NW Turkey obtained by numerous permanent seismic stations from different local and regional networks. The substantially improved velocity model will allow for reliable absolute hypocenter determination which is of relevance especially in the light of the expected major (M7+) earthquake in the vicinity of the population center of Istanbul, where a combined surface and borehole-based seismometer network is to be installed in the frame of the ICDP-GONAF project. We expect to provide the first regional 3D-velocity model for this key-region.

精确的三维速度结构知识是利用高精度震源定位对目标区域进行构造表征的重要先决条件。在这方面，从广泛的波形数据档案中选择精确的相位到达时间是最重要的输入参数。该项目的目的是开发用于地壳相位自动识别和准确定时及其反演的算法，以导出土耳其西北部更广泛的马尔马拉地区的三维速度模型。基于自动P相和s相选择算法的最新发展，计划将这些算法扩展并应用于其他地壳和上地幔相，如Pg， Pn， PmP及其s波垂部。基于最近的结果，我们将使用统计建模、多元时间序列分析和启发式方法。新方法还应提供可靠的、非离散的和非对称的误差估计。不同识别相位开始的到达时间将作为非线性定位方法（如NonLinLoc和VELEST）的输入，以建立最小一维速度模型，然后将作为使用SIMULPS14进行3d反演的起始模型。新开发的算法将应用于土耳其西北部马尔马拉地区的当地和区域地震记录，这些记录是由来自不同地方和区域网络的许多永久地震台站获得的。大大改进的速度模型将允许可靠的绝对震源确定，特别是考虑到伊斯坦布尔人口中心附近预计发生的大地震（M7+），在ICDP-GONAF项目的框架内，将在那里安装一个地面和钻孔联合地震仪网络。我们希望为这个关键区域提供第一个区域3d速度模型。