フィリピン海スラブの沈み込みに伴う温度・速度構造とスラブ内地震・地表変形の地域性

与菲律宾海板片俯冲相关的温度和速度结构以及板片内地震和表面变形的区域特征

• 批准号: 14540397
• 负责人: YOSHIOKA Shoichi
• 金额: $ 2.11万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540397/
• 关键词: Philippine Sea plate; simulation of temperature and flow; interplate large earthquake; 低周波微動; 非地震性すべり; スラブ; 温度分布; 地殻熱流量; 南海トラフ; 四国海盆

1.Development and modeling of 3-D source code of temperature and flowBased on 2D finite-difference source code of temperature and flow, we completed finite-difference source code of a 3D rectangular parallelepiped model. We non-dimensionalized parameters, parallelized and made the source code faster, and developed visualization tools for calculated results. Using the source code, we constructed 3D subduction model of temperature and flow in southwest Japan, taking account of past subducting history of the Philippine Sea plate, oblique subduction, and different temperature boundary conditions due to difference in distance from the strike of the Kinan seamount chain. Comparing observed heat flow data with calculated ones, we proposed new temperature distribution on the upper surface of the subducting Philippine Sea plate, and succeeded in estimation of seismogenic zone of the Tonankai and the Nankai earthquakes.2.Estimation of interplate coupling off Shikoku to off east Kyushu and examination of regional difference in Earth's surface deformationWe revealed relation between interplate coupling in Hyuganada region and crustal deformation in Kyushu region from an inversion analysis of GPS data. As a result, we found that crustal deformation in Kyushu can be characterized by right-lateral motion at a deeper portion of the Beppu-Shimabara graben and southeastward mantle drag, which would be caused by horizontal flow of mantle plume which is produced under the Okinawa trough, in addition to interplate coupling in the Hyuganada region. Moreover, we estimated interplate coupling off Shikoku from GPS data inversion. We also estimated relation between coseismic slipped region associated with the 1968 Hyuganada (M7.5) and the 1946 Nankai (M8.1) earthquakes and spatial distribution of interplate coupling obtained in this project, and recurrence time of these earthquakes.

1、3维温度和流量源代码开发与建模基于2维温度和流量有限差分源代码，完成了3维长方体模型的有限差分源代码。我们对参数进行无量纲化，并行化并使源代码更快，并开发了计算结果的可视化工具。使用源代码，我们构建了日本西南部温度和流量的 3D 俯冲模型，考虑到菲律宾海板块过去的俯冲历史、倾斜俯冲以及由于距纪南海山走向不同而导致的不同温度边界条件链。通过将实测热流数据与计算数据进行比较，提出了俯冲菲律宾海板块上表面的新温度分布，并成功地估计了东南海地震和南海地震的发震带。2.四国与近海板间耦合的估计东九州与地表形变的区域差异研究通过GPS数据的反演分析，揭示了Hyuganada地区的板间耦合与九州地区的地壳形变之间的关系。结果发现，九州地壳变形的特征是别府-岛原地堑深部的右旋运动和向东南的地幔拖曳，这可能是由冲绳地幔下方产生的地幔柱的水平流动引起的。除了Hyuganada 地区的板间耦合之外，还存在海槽。此外，我们还根据 GPS 数据反演估计了四国附近的板间耦合。我们还估计了与 1968 年 Hyuganada (M7.5) 和 1946 Nankai (M8.1) 地震相关的同震滑移区域与本项目中获得的板间耦合空间分布之间的关系，以及这些地震的复发时间。

项目成果

"プロフェッショナル英和・和英辞典 工学物質篇(テラ)"小学館. (2004)

《专业英日/日英词典工程材料版（Terra）》小学馆（2004）。