WEKO3
アイテム
Morphology of the Intraslab Seismic Zone and Devolatilization Phase Equilibria of the Subducting Slab Peridotite
https://doi.org/10.15083/0000032600
https://doi.org/10.15083/00000326000ecc8790-f602-438b-8e7a-112f1a5751d7
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
ji0764003.pdf (4.0 MB)
|
|
| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2008-05-30 | |||||
| タイトル | ||||||
| タイトル | Morphology of the Intraslab Seismic Zone and Devolatilization Phase Equilibria of the Subducting Slab Peridotite | |||||
| 言語 | en | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | dehydration | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | earthquake | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | subduction zone | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | phase equilibria | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | double seismic zone | |||||
| 資源タイプ | ||||||
| 資源 | http://purl.org/coar/resource_type/c_6501 | |||||
| タイプ | departmental bulletin paper | |||||
| ID登録 | ||||||
| ID登録 | 10.15083/0000032600 | |||||
| ID登録タイプ | JaLC | |||||
| その他のタイトル | ||||||
| その他のタイトル | スラブ内地震の分布形態と沈み込むスラブかんらん岩中の脱水反応 | |||||
| 著者 |
Omori, Soichi
× Omori, Soichi× Kamiya, Shin'ichiro× Maruyama, Shigenori× Zhao, Dapeng |
|||||
| 著者別名 | ||||||
| 識別子Scheme | WEKO | |||||
| 識別子 | 126132 | |||||
| 姓名 | 大森, 聡一 | |||||
| 著者別名 | ||||||
| 識別子Scheme | WEKO | |||||
| 識別子 | 126133 | |||||
| 姓名 | 神谷, 眞一郎 | |||||
| 著者別名 | ||||||
| 識別子Scheme | WEKO | |||||
| 識別子 | 126134 | |||||
| 姓名 | 丸山, 茂徳 | |||||
| 著者別名 | ||||||
| 識別子Scheme | WEKO | |||||
| 識別子 | 126135 | |||||
| 姓名 | 趙, 大鵬 | |||||
| 著者所属 | ||||||
| 著者所属 | Department of Earth and Planetary Sciences, Tokyo Institute of Technology | |||||
| 著者所属 | ||||||
| 著者所属 | National Research Institute for Earth Science and Disaster Prevention | |||||
| 著者所属 | ||||||
| 著者所属 | Institute for Frontier Research on Earth Evolution, Japan Marine Science and Technology Center | |||||
| 著者所属 | ||||||
| 著者所属 | Department | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | The dehydration-induced earthquake hypothesis for intermediate-depth earthquakes in a subduction zone was examined semi-quantitatively in the light of multi-component phase equilibria of the mantle. Based on the expected dehydration equilibria in subducting peridotite, we found a further organized structure in the hypocentral distribution observed in northeast Japan to the double seismic zone (DSZ). The structure of the seismic zone is possibly controlled by a chemical rather than a mechanical process. We first constructed a phase diagram in the model system MgO-Al2O3-SiO2-H2O (MASH) using thermodynamic calculations. Then possible hypocenter distributions in subducting mantle were semi-quantitatively predicted on the assumption that: 1) any dehydration induces earthquakes; 2) a subducting slab is more or less hydrated; 3) hydrated mantle is approximated by the MASH model system; and, 4) dehydration proceeds near equilibrium. The predicted topology of dehydrationinduced seismic zones reproduces the double seismic zone (DSZ); also predicted are multiple seismic zones, multiple convergences of the seismic planes, and thermal structure dependence of the convergence depth of the DSZ. These predictions are compared to seismic observations in NE Japan and the world's subduction zones. In NE Japan, the geometry of the double seismic zone and the hypocenter clusters between the double seismic planes compare well to the predicted dehydrationinduced multiple seismic zones and multiple convergences, assuming a simple prograde P-T path for the coldest thermal center of the slab. The correlation of the age of the subducting plate and the depth of the convergence of the world's DSZ is also consistent with the prediction. The assumption of a hydrated mantle is examined by seismic tomography beneath the Kanto area. The Poisson's ratio calculated between the two seismic planes at a depth ca. 50-80 km suggests the existence of serpentinized peridotite in the subducting mantle at those depths, even though the degree of hydration is not so strong (ca. 50-30%) and is heterogeneous. Transform faults, oceanic fracture zones, and faults at the trench are all considered to be possible hydration sites of the oceanic mantle. Using the dehydration induced-earthquake model, the link between the dehydration and the seismic zone provides us with the thermal structure in the subducting slab. The estimated thermal structure exhibits a higher temperature than previous numerical simulations, particularly within the slab. Our estimate suggests viscous heating has been underestimated in previous numerical simulations and heat transfer by a fluid produced by the dehydration of the slab mantle must be included in the model. The dehydration model is also applicable to deep seismicity in the mantle transition zone. | |||||
| 書誌情報 |
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo 巻 76, 号 4, p. 455-478, 発行日 2002-03-25 |
|||||
| ISSN | ||||||
| 収録物識別子タイプ | ISSN | |||||
| 収録物識別子 | 00408972 | |||||
| 書誌レコードID | ||||||
| 収録物識別子タイプ | NCID | |||||
| 収録物識別子 | AN00162258 | |||||
| フォーマット | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | application/pdf | |||||
| 日本十進分類法 | ||||||
| 主題Scheme | NDC | |||||
| 主題 | 458 | |||||
| 出版者 | ||||||
| 出版者 | 東京大学地震研究所 | |||||
| 出版者別名 | ||||||
| Earthquake Research Institute, University of Tokyo | ||||||
