钻孔应变观测中潮汐因子离散性与各向异性原因探讨——“十五”数字地震观测网络分量钻孔应变仪首批观测资料分析解释

中国数字地震观测网络"十五"计划期间,在全国布设约40台我国自主研发的YRY-4型分量式钻孔应变仪.现已取得一批固体潮观测数据,计算M2波潮汐因子的结果表明,潮汐因子的相对精度最高达到了0.001.在此基础上,发现各观测点潮汐响应(潮汐因子)与理论模型比较有很大的离散性及有规律的方位各向异性.本文提出断层隔离是造成各台站潮汐因子偏离理论值及方位各向异性的主要原因.有限元断层地块模型应变方位响应与台站实测方位响应的一致,支持了这一观点.潮汐响应各向异性现象有望在地质构造研究、城市断层探测、地块活动微动态、地震烈度区划等研究领域发挥作用.也可为GPS等空间大地测量观测数据改进潮汐位移修正,提供参考.

Discussion on strain tidal factor separation and anisotropy——Analysis of first data of borehole component strain-meter of China's digital seismological observational networks

The National Digital Seismological Observational Networks plans to install in China's mainland 40 YRY-4 Borehole Strain meters developed by CHI Shun-liang.First set of data has been analysesed,and from the best quality data,relative accuracy of M2 wave factor can reach 0.001,which is better than the best long-base cave strain meters.We also discovered at various borehole strain-meter stations tidal response(tidal factor) are separate and have orderly anisotropy.We believe that fault isolation is the cause of separation and anisotropy.Finite element model of fault block's azimuth response has contingency with measured response,which supports this hypothesis.The anisotropy of tidal response will be helpful at geologic structure research,city fault survey,land block micro activity,earthquake intensity area delimit.And it can also improve tidal displacement revises of GPS data.