摘要
利用昌黎、红山等台站的地磁 Z 分量日变资料，分析了磁静日幅度、磁扰日幅度和磁静日低点时间的年变化与长期变化，结果年变化和长期变化都非常明显。磁静日幅度的长期变化量可达 14～15 nT；磁静日低点时间的年变化，提前区与滞后区低点时间最大可相差 42 min。而低点时间的长期变幅度化幅度一般 50 min 左右，且长期变化量由西向东有逐渐减小趋势，最大与最小两台时差可达 21 min。长期变幅最小的 2 个台为文安和昌黎，可能与海水影响有关。
The magnetically quiet day and magnetically disturbed day as well as the low point time at the magnetically quiet day are analyzed by the annual variation and secular variation of geomagnetic Z component datum observed at Changli and Hongshan Stations. The results show that the annual variation and secular variation are very obvious, and the secular variation at magnetically quiet day is taken to 14～15 nT. The annual variation of low point time at magnetically quiet day shows that there are 42 minutes maximal difference between the advance and lag field at low point, and the secular variation possesses the decrease tendency from west to east. Maximum and minimum time differences are taken to 21 minutes between two stations. Minimum magnitude of the secular variation is Wen′an and Changli Station; it is considered that the seawater may influence them.
出处
《地震地磁观测与研究》
2004年第1期52-56,共5页
Seismological and Geomagnetic Observation and Research
关键词
地磁场
地磁Z分量
日变化
磁静日
磁扰日
低点时间
Z component of geomagnetism,daily variation,magnetically quiet day,magnetically disturbed day,low point time
