Borehole Seismogram Calibration and Deconvolution for Ground Motion and Earthquake Source Studies: Applications to the ICDP-GONAF project in NW Turkey

用于地面运动和地震源研究的钻孔地震图校准和反褶积：在土耳其西北部 ICDP-GONAF 项目中的应用

基本信息

批准号：
235773915
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：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/235773915?language=en
关键词：
Borehole Seismogram Calibration Deconvolution Ground

项目摘要

During the initial 1.5-year period of the project we focused on analyzing seismic recordings from the first vertical seismometer array implemented in the frame of the ICDP-GONAF project, located on the Tuzla peninsula in SE Istanbul. Due to the low-noise conditions and resulting high signal-to-noise ratios at the downhole stations compared to surface stations it was possible to detect numerous microseismic (M<1) events which went undetected by surface arrays. In the frame of the here proposed extension we intend to further enlarge the event data base for the eastern Sea of Marmara by integrating additional recently completed GONAF borehole arrays on the Armutlu peninsula (completed in summer 2014) as well as up to four more arrays which are currently drilled and that shall be in operation by spring 2015 (e.g. on the Princes Islands). For the investigation of the near-surface properties at the Tuzla site such as the velocity structure and attenuation we applied several different techniques. The same methods will be applied to the new GONAF stations to evaluate whether our observations at the Tuzla site are site-specific or transferable also to other geological formations. The comparative analysis of different sites will be of great value for developing a data analysis scheme that also corrects for site effects, a procedure needed to improve for example earthquake source parameter estimations. Furthermore we plan to apply processing techniques from vertical seismic profiling for fault-zone imaging of the NAFZ fault branches below the eastern Sea of Marmara. To do so we will select local seismicity within 20 km epicentral distance (depth range 5-20km) to the GONAF stations and use the different depth levels of the borehole sensors. The waveform recordings of 3-component 1Hz MARK seismometers deployed at 300 m depth for the first time will be studied and are expected to provide new insights in shear-wave characteristics of the study area.

在该项目的最初 1.5 年期间，我们重点分析了 ICDP-GONAF 项目框架内实施的第一个垂直地震仪阵列的地震记录，该项目位于伊斯坦布尔东南部的图兹拉半岛。与地面站相比，由于井下站的低噪声条件和由此产生的高信噪比，因此可以检测到地面阵列未检测到的大量微震（M<1）事件。在此处提议的扩展框架中，我们打算通过集成最近在 Armutlu 半岛上完成的 GONAF 钻孔阵列（于 2014 年夏季完成）以及最多四个阵列，进一步扩大马尔马拉海东部的事件数据库。目前正在钻探，将于 2015 年春季投入运行（例如在王子群岛）。为了研究图兹拉遗址的近地表特性（例如速度结构和衰减），我们应用了几种不同的技术。同样的方法将应用于新的 GONAF 站，以评估我们在图兹拉站点的观测是否是针对特定地点的，还是也可以转移到其他地质构造。不同地点的比较分析对于开发数据分析方案具有重要价值，该方案还可以校正场地影响，这是改进地震源参数估计等所需的程序。此外，我们计划应用垂直地震剖面处理技术对马尔马拉海东部下方的 NAFZ 断层分支进行断层带成像。为此，我们将选择距 GONAF 台站 20 公里震中距离（深度范围 5-20 公里）内的当地地震活动，并使用不同深度级别的钻孔传感器。将首次对部署在300 m深度的三分量1Hz MARK地震仪的波形记录进行研究，预计将为研究区的剪切波特征提供新的见解。