基于中国地磁图的西藏地磁测量对比分析

Comparative Analysis on Magnetic Survey in Tibet Region Base on China Geomagnetic Chart

详细论述了《2005.0中国地磁图》、《2010.0中国地磁图》西藏测区的两次测点点位勘选及测量工作过程,通过大量的、与规范指标要求相关的数据分析,说明了野外观测质量的可靠性,并对通化后的2期数据进行对比研究。结果表明:2005～2010年在西藏测区覆盖范围,磁偏角零等值线向西偏移,偏移量约为0.4°;地磁场总强度平均增加值为206nT,磁倾角的平均增值为0.45°。

We expound geomagnetic stations selection and surveying work of twice geomagnetic survey for ＂2005.0 China geomagnetic charts＂ and ＂2010.0 China geomagnetic charts＂ in Tibet.It is proved that the quality of field survey is reliable by analyzing abundant data which is related to the demands of criterion.Through comparative analyzing on the corrected data of the first and the second period,we conclude that the zero constant value line of geomagnetic declination offset toward west,and the deviant is about 0.4.The average increment of geomagnetic field total intensity is 206 nT,and the average increment of geomagnetic incidence is 0.45° from 2005 to 2010 in the surveying region of Tibet.