重力仪一次项系数对重力场动态变化的影响研究

Research on the Effect of One Degree Term of Chromatic Polynomial of Gravimeter on Gravity Dynamic Change

利用2011~2013喜马拉雅项目在南北地震带北段获得的10余个绝对重力值作为基准,运用甘肃、宁夏和河西3个重力网的数据对各重力仪一次项系数进行重新解算,获得重力场动态变化。结果显示：1）2011-05~2013-06的重力场反映出,青藏高原深部物质向北东运移过程中出现自西南向东北、由负向正的大空间尺度趋势性显著重力变化;2）LCR-G型及Burris型金属弹簧重力仪的一次项较稳定,基本不变,而CG-5型石英弹簧重力仪的一次项逐年减小,应每年利用绝对基准进行实测标定;3）利用绝对基准进行实测一次项标定后,重力场总的变化趋势与利用长基线标定的一次项计算结果基本一致,只是量级有所减小。

On the basis more than ten absolute gravity values of the Himalayaproject in the north and the south segments during 2011-2013,gravity dynamic variations are obtained according to the recalculated one-degree term of chromatic polynomial of gravimeter in the network of Gansu,Ningxia and Hexi.The results show：1）Gravity variation is fairly dramatic in the Qinghai-Tibet plateau,which reflects tendency change on large spatial scales in the process that deep material moves to the northeast.2）One-degree term of chromatic polynomial remains stable with respect to LCR-G and Burris;CG-5decreased gradually（it should be calibrated according to the absolute values）.3）A general tendency of change of gravity variation after we used absolute values to calibrate the one-degree term of chromatic polynomial is consistent with long baseline calibration,data analysis is more reliable which is decreased.