郑州地震监测中心站连续重力仪背景噪声水平分析  

Analysis of the background noise level of continuous gravimeter at Zhengzhou Seismic Monitoring Center Station

作　　者：张诺男 赵祖虎 陈力刚 林景枝 ZHANG Nuonan;ZHAO Zuhu;CHEN Ligang;LIN Jingzhi(Zhengzhou Earthquake Monitoring Center Station,Henan Province 450062,China;Henna Earthquake Agency,Zhengzhou 450000,China)

机构地区：[1]郑州地震监测中心站,中国河南450062 [2]河南省地震局,中国郑州450000

出　　处：《地震地磁观测与研究》2022年第5期79-85,共7页Seismological and Geomagnetic Observation and Research

基　　金：中国地震局监测、预报、研究三结合课题“结合重力仪与宽频带地震仪分析郑州地震台重力数据干扰数据特性”(项目编号:3JH-2021031)。

摘　　要：选取2009—2019年郑州地震监测中心站连续重力观测数据,结合地震频段观测数据精度,分析中心站背景噪声水平,结果发现:①潮汐和气压等因素对重力观测数据的亚地震频段和潮汐频段的平均功率谱密度值(PSD)影响较大,在地震频段影响较小;②通过对月地震噪声等级值(SNM)的分析,发现较小值多集中在每年2月(农历春节前后);③在研究时段内,地震频段噪声等级SNM值范围在(3.107—3.268)×10^(-16)(m·s^(-2))^(2)/Hz,重力固体潮汐观测精度P_(L)范围在(0.130—0.278)×10^(-8)(m·s^(-2))·(Hz·s)^(-1/3),与gPhone-1相对重力仪相比,PET重力仪观测数据存在一定漂移,其P_(L)数值略大,表明观测环境和仪器性能共同制约着重力观测精度。Selecting continuous gravity observation data at the Zhengzhou Seismic Monitoring Center Station from 2009 to 2019,combined with the accuracy of the seismic frequency observation data,this study analyzed the background noise level of the station.The results show that the influence of tide and air pressure on the average power spectral density value(PSD)is great in the sub-seismic and tide frequency bands,but small in the seismic frequency band;②Through the analysis of the monthly seismic noise magnitude(SNM),it is found that the smaller value is mostly concentrated in February every year(before and after the Lunar New Year);③During the study period,the SNM value of the noise level in the seismic frequency band is in the range of(3.107-3.268)×10^(-16)(m·s^(-2))^(2)/Hz,the observation accuracy of gravity solid tidal is in the range of(0.130-0.278)×10^(-8)(m·s^(-2))·(Hz·s)^(-1/3).Compared with the gPhone-1 relative gravimeter,the observation data of the PET gravimeter has a certain drift,and its P_(L) value is slightly larger,indicating that the observation environment and instrument performance jointly control the accuracy of gravity observation.

关 键 词：连续重力 背景噪声 平均功率谱密度(PSD) 地震噪声等级(SNM) 

分 类 号：P315.726[天文地球—地震学]