| 利用近场强震记录反演2016年日本熊本县地震震源破裂过程 |
| |
| 引用本文： | 郑傲, 王铭锋, 章文波. 2017. 利用近场强震记录反演2016年日本熊本县地震震源破裂过程. 地球物理学报, 60(5): 1713-1724, doi: 10.6038/cjg20170509 |
| |
| 作者姓名： | 郑傲 王铭锋 章文波 |
| |
| 作者单位： | 中国科学院大学地球科学学院, 北京 100049 |
| |
| 基金项目： | 国家自然科学基金项目（41274068，41674056），中国科学院国家外国专家局创新团队国际合作伙伴计划（KZZD-EW-TZ-19）联合资助. |
| |
| 摘 要： | 2016年4月15日16时25分（UTC），日本熊本县发生MW7.1强烈地震，给当地人员、建筑及经济造成严重灾难和巨大损失.日本地震观测网F-net给出的震源机制解显示此次地震的震源位置为130.7630°E，32.7545°N，深度12.45 km，节面Ⅰ：走向N131°E、倾角53°、滑动角-7°；节面Ⅱ：走向N226°E、倾角84°、滑动角-142°.与此同时，余震的震中分布及其震源机制结果显示主震的震源机制在破裂过程中有可能发生了变化，单一的震源机制不足以充分解释观测数据.本文依据GNSS和InSAR地表形变反演结果为约束，并结合活动构造资料为参考，构建了震源机制变化的有限断层模型，采用水平层状介质模型，利用日本强震观测台网K-NET和KiK-net的近场加速度观测记录，通过多时间窗线性波形反演方法反演了此次地震的震源破裂过程.研究结果显示，这是一次沿Futagawa-Hinagu断层带发生的右旋走滑破裂事件，发震断层分为南北两段，其中北段走向N235°E、倾角60°，南段走向N205°E、倾角72°，断层深度范围和余震深度分布基本一致，断层面上滑动主要集中于断层北段，最大滑动量约7.9 m，整个断层的破裂过程持续约18 s，释放地震矩5.47×1019 N·m（MW7.1）.
|
| 关 键 词： | 熊本地震 震源破裂过程 近场强震记录 波形反演 有限断层模型 |
| 收稿时间： | 2016-08-22 |
| 修稿时间： | 2017-03-02 |
Source rupture process of the 2016 Kumamoto prefecture,Japan, earthquake derived from near-source strong-motion records |
| |
| ZHENG Ao, WANG Ming-Feng, ZHANG Wen-Bo. 2017. Source rupture process of the 2016 Kumamoto prefecture, Japan, earthquake derived from near-source strong-motion records. Chinese Journal of Geophysics (in Chinese), 60(5): 1713-1724, doi: 10.6038/cjg20170509 |
| |
| Authors: | ZHENG Ao WANG Ming-Feng ZHANG Wen-Bo |
| |
| Affiliation: | College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China |
| |
| Abstract: | On 15 April, 2016 (UTC) a great earthquake of magnitude MW7.1 occurred in Kumamoto prefecture, Japan. The strong shocking of the earthquake caused grave disasters and severe damages. The focal mechanism solution released by F-net of NIED of Japan indicates that the hypocenter is at 130.7630°E, 32.7545°N, and a depth of 12.45 km. For nodal plane I, the strike is N131°E, the dip is 53°, and the rake angle is -7°; for nodal plane II the strike is N226°E, the dip is 84°, and the rake angle is -142°. The epicenter distribution and focal mechanisms of its aftershocks imply that the mechanism of the mainshock may have changed during the source rupture process, thus a single focal mechanism is not enough to explain the source process adequately. In this study, based on the inversion result of GNSS and InSAR surface deformation, with active structures for reference, we construct a finite fault model with focal mechanism changes, and derive the source rupture process by multi-time-window linear waveform inversion method using the strong-motion data (0.05~1.0 Hz) obtained by K-NET and KiK-net of Japan. Our result shows that the Kumamoto earthquake is a right-lateral strike slipping rupture event along the Futagawa-Hinagu fault zone, and the seismogenic fault is divided into a northern segment and a southern one. The strike and the dip of the northern segment are N235°E, 60° respectively. And for the southern one, they are N205°E, 72° respectively. The depth range of the fault model is consistent with the depth distribution of the aftershocks, and the slip on the fault plane is mainly concentrated on the northern segment, in which the maximum slip is about 7.9 meters. The rupture process of the whole fault continues for approximately 18 seconds, and the total seismic moment released is 5.47×1019 N·m (MW7.1). |
| |
| Keywords: | Kumamoto earthquake Source rupture process Near-source strong-motion records Waveform inversion Finite-fault model |
|
| 点击此处可从《地球物理学报》浏览原始摘要信息 |
|
点击此处可从《地球物理学报》下载免费的PDF全文 |
|
