Earthquake source process analysis codes incorporeting the effect of the heterogeneous structure at the subduction zone.

纳入俯冲带非均质结构影响的地震源过程分析代码。

• 批准号: 08640527
• 负责人: OKAMOTO Taro
• 金额: $ 1.41万
• 依托单位: TOKYO INSTITUTE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640527/
• 关键词: seismic waves; source process; moment tensor; 沈み込み帯; 差分法; 地震波理論

(1)Far field body wave codeA new, very effective 2.5D plane wave propagation FDM code based on Takenaka & Kennet (1996) algorithm has been developed by co-working with them (Takenaka and Kennett), It is much faster than the previous one (more than 10 times faster). We expect it is applied to various problems including our own research.2)Near field complete seismic waveform codeWe have verified the accuracy for the fluid-solid boundaries for finite-difference method and have found a proper grid arrangement to improve the accuracy. The resultant code generates waveforms that matches well with the observed waveforms for the seismo-acoustic environment.3)Moment tensor inversion by using near-field full waveformsWe have developed a method based on the reciprocal theorem. This method can generate Green's functions for a station and various source locations in a single calculation. It is considered that this approach will become one of the standard method. We tested the fundamental aspects of … More this method by applying our code for a shallow earthquake at Japan Trench and obtained a very reasonable inversion result. This ensures the applicability of the approach.4)Far fried body waveform analysis codeWe have developed two codes : one is to determine the source mechanism and the source position and the other is to determine the distribution of the moment release on a fault, In the latter code, we have formulated a non-linear inversion procedure to avoid a negative moment. We have applied our new method to the analysis of 1992 Nicaraguan Tsunami earthquake for which a very shallow moment release is suggested by tsunami waveform analysis. Our result based on the seismic waveforms suggest a relatively deep moment release.5)Parallel codeWe have used the standard mechanism for inter-process communications on UNIX OS to implement a parallel functionality in our near-field waveform code. For a dual processor calculation, we observed a 1.5 times acceralation against a single processor calculation. Our code has not achieved the optimum parallelism and further study will be required. Less

（1）远场体波程序本文与Takenaka和Kennet（1996）合作，在Takenaka和Kennet（1996）算法的基础上，开发了一种新的、非常有效的2.5维平面波传播FDM程序，它比以前的程序快10倍以上。2）近场全波波形程序我们验证了有限差分法流固边界的精度，并找到了一种适当的网格排列方式来提高精度。3）近场全波矩张量反演我们提出了一种基于互等定理的矩张量反演方法。该方法可以在一次计算中生成一个台站和多个源位置的绿色函数。据认为，这种方法将成为标准方法之一。我们测试了 ...更多信息 并将该方法应用于日本海沟的一次浅源地震，得到了非常合理的反演结果。4）远炸体波形分析程序我们开发了两个程序：一个是确定震源机制和震源位置，另一个是确定断层上释放力矩的分布。在后一个程序中，我们制定了一个非线性反演程序，以避免负力矩。我们已将新方法应用于1992年四川海啸地震的分析，海啸波形分析表明，该地震存在一个非常浅的力矩释放。我们基于地震波形的结果表明了一个相对较深的矩释放。5）并行代码我们使用UNIX操作系统上的标准进程间通信机制在我们的近场波形代码中实现了并行功能。对于双处理器计算，我们观察到单处理器计算的1.5倍加速。我们的代码还没有达到最佳的并行性和进一步的研究将是必要的。少

项目成果

竹中博士,岡元太郎: "2.5次元弾性平面入波射問題の時間領域差分解法" 地球惑星科学関連学会1997年合同大会予稿集. E42-06 (1997)

Takenaka、Gentaro Oka 博士：“2.5 维弹性平面入射波注入问题的时域微分分解方法”1997 年地球与行星科学协会联合会议论文集 E42-06 (1997)。

Takenaka, H.and T.Okamoto: "2.5D finite-difference modeling of teleseismic waveform" Final program and Abstracts, 75., 4th SIAM Conference on Mathematical and Computational Issues in the Geosciences (June 16-19,1997, Albuquerque, New Mexico, USA).

Takenaka, H. 和 T.Okamoto：“远震波形的 2.5D 有限差分建模”最终程序和摘要，75。，第四届 SIAM 地球科学数学和计算问题会议（1997 年 6 月 16 日至 19 日，阿尔伯克基，新

H.Takenaka and T.Okamoto: "A time-domain FDM for 2.5-D elastic plane-wave incidence problems" Abstracts of Japan Earth and Planetary Science Joint Meeting. E42-06 (1997)

H.Takenaka 和 T.Okamoto：“用于 2.5 维弹性平面波入射问题的时域 FDM”日本地球与行星科学联席会议摘要。

岡元太郎: "Complete 2.5D-FDM Seismogram for Shallow Subduction Zone Earthquakes(2): Comparison with Observed Data" 地球惑星科学関連学会1997年合同大会予稿集. w12-P17 (1997)

Taro Okamoto：“浅俯冲带地震的完整 2.5D-FDM 地震图（2）：与观测数据的比较”1997 年地球与行星科学协会联合会议论文集 w12-P17（1997）。

竹中博士,岡元太郎: "遠地実体波の非常に効率的な2.5次元計算法" 日本地震学会講演予稿集. No.2. B65 (1997)

Takenaka、Gentaro Oka 博士：“远距离体波的非常有效的 2.5 维计算方法”，日本地震学会论文集，第 2 期 B65（1997 年）。