震源核形成にともなうプレスリップの検出 (ひずみ場のマッピング)

检测与震源成核相关的预滑移（应变场映射）

• 批准号: 15740275
• 负责人: 川方 裕則
• 金额: $ 1.92万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15740275/
• 关键词: プレスリップ; 震源核成長過程; ひずみ局所化; 非弾性剪断変形; 震源核; ひずみ; 三軸圧縮試験; 花崗岩

地殻内部で発生する地震現象には震源核形成過程が先行し,震源核成長過程にはプレスリップを伴うことが提唱され,地震予知の可能性はこの検出にすべてが託されているといっても過言ではない.プレスリップをコントロールする要因を明らかにし,その発現形態が断層面の一部にとどまるのか,同時に複数の領域で成長するのか,断層面全体にわたって現れるのか,について調べることは重要である.本研究では,既存断層面をもつ岩石試料表面におけるひずみ場をマッピングする.そしてひずみ記録に前兆的変動(プレスリップに伴う歪み)が検出できるか否かを調べ,検出できるとすればその発現パターンを調べることを目的として実施された.また,震源核で発生するAEの特徴を探り,震源核成長過程の理解も同時に目指すこととした.Westerly花崗岩試料を用いて,常温・封圧下(100MPa)で三軸圧縮試験を実施し,試料表面および内部の一部に既存断層を形成させた.得られた試料に対して,X線CTスキャナを使用して断層面の内部構造の非破壊検査を実施した.その後,試料表面に3成分ひずみゲージおよびAEセンサを配置させ,再度同一条件下にて三軸圧縮試験を実施した.その結果,断層面成長・すべり過程におけるひずみ変化に関して次のようなシナリオを得た.1)断層端付近でのみ断層の非弾性剪断変形による接線ひずみの局所化,ひずみ主軸の回転が生じる.2)断層端が通過した後,さらに非弾性ひずみが蓄積することにより,相対変位が生じる.3)ひずみの局所化を経験した領域は,再び載荷されても,充分に固着していなければ局所化は起こさない.また,震源核近傍で発生するAEの波形は,レーザードップラー速度計による簡易較正の結果,インタクト(無垢)領域で発生するAEに比べ,やや長周期が卓越する可能性が示された.この結果は,広帯域AEセンサ等を利用してさらに詳細を調べる必要がある.

The formation of the source core of an earthquake in the interior of the earth is prior to the formation of the source core, and the growth of the source core is accompanied by the singing of the earthquake, and the possibility of an earthquake is known. It is important to know that there is a significant increase in the number of data in the field, and that all the data in the field are growing, and all the fault planes are important. In this study, both the surface and the surface of the rock material were cut off. If you are not aware of the warning signs, you can tell whether or not to do so, and that you will be able to do so in order to show that you are in good condition. During the growth process of the source core, it is understood that the temperature at the same time refers to the temperature of the atmosphere. The westerly flower rock material is used in the atmosphere, and under the normal temperature seal (100MPa), the ambient temperature is sealed under the ambient temperature (100MPa). There is an existing temperature in the surface of the material. In order to improve the quality of the material, the X-ray CT equipment uses the internal parts of the broken surface to make a non-destructive device. After that, the raw material surface is made up of 3 components, and the material surface is used again under the same conditions. The material surface is composed of three components, three components and three components. According to the results of the test, the fault surface is growing, the process is stable, and the secondary fault is successful. 1) the end of the breaker is paid near the cutoff end of the cutoff. The connection of the cutoff is localized, and the switch is localized. 2) after the cut-off end is switched on, the interconnection is localized. 2) after the cut-off end is connected through the switch, the non-destructive switch is stored in the terminal. Relative to each other, we need to know how to localize your domain, and then make sure that it is fully fixed and localized. Near the source core, near the source core, the AE waveform is generated, the velocity is measured, and the results are correct. In the (scale-free) field, the AE waveform is measured, and the possibility of long-period performance is shown. The results show that the domain AE administrator and so on are required to make full use of the necessary information.