权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Study on the Direction of Arrival of Geothermal Seismic Noise

地热地震噪声到达方向研究

基本信息

批准号：
63550458
负责人：
SAITO Tokumi
金额：
$ 1.28万
依托单位：
Iwate University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550458/
关键词：
Geophysical exploration Geothermal seismic noise Direction of arrival Tripatite method Particle motion method Correlation method Geothermal reservoir 微動粒子軌道トリパタイト

项目摘要

Geothermal seismic propagation at the Kakkonda geothermal area and the eastern region of Hachimantai was investigated by the 3 components - 1 station method and tripartite method respectively. Softwares were developed using an NEC 9800 computer to determine the directionality of seismic noise propagation. The results obtained are summarized as under.1. The directionality of geothermal seismic noise arrival at the Kakkonda geothermal area investigated by the particle motion and cross correlation based on the 3 components - 1 station method does not necessarily coincide with the direction of a geothermal reservoir presumed to exist. However, 3 components - 1 station observation is considered for determining the direction of geothermal seismic noise arrival, since it enables approximate estimation of the direction by undertaking survey at a large number of observation sites and it facilitates observation even at areas not large enough to secure long measuring lines due to topographic limitations.2. Observation by the tripartite method at the eastern region of Hachimantai showed that the geothermal seismic noise at this region had a uniform direction of arrival and was originated from a relatively deep subterranean area. This suggested the applicability of this method to the prospecting of a geothermal reservoir, although the source of tremor cannot be affirmatively specified due to inadequacy of knowledge on the geothermal structure of this area.3. In this study, a basic system could be established for the analysis of the directionality of tremor arrival at geothermal areas by the 3 components - 1 station and tripartite observation methods. Further evaluation of the effectiveness of geothermal seismic noise survey is required by accumulation of survey data at an increased number of geothermal areas.

分别采用三分量一站法和三方法对Kakkonda地热区和八幡平东部地区的地热地震传播进行了研究。使用 NEC 9800 计算机开发软件来确定地震噪声传播的方向性。所得结果总结如下： 1．通过基于 3 分量 - 1 站法的质点运动和互相关研究到达 Kakkonda 地热区的地热地震噪声的方向性不一定与假定存在的地热储层的方向一致。然而，在确定地热地震噪声到达方向时，考虑了“三分量一站观测”，因为它可以通过在大量观测点进行测量来大致估计方向，并且即使在由于地形限制而不足以确保长测量线的区域也有利于观测。 2．通过三方法对八幡平东部地区的观测表明，该地区的地热地震噪声到达方向一致，来源于较深的地下区域。尽管由于对该地区地热结构认识不足而无法确定震源，但这表明该方法在地热储层勘探中的适用性。 3．本研究通过三分量一站三方观测方法，建立了地热区地震波到达方向性分析的基本体系。随着越来越多的地热地区的调查数据的积累，需要进一步评估地热地震噪声调查的有效性。