地震研究

利用2003和2013年的GRACE月重力场模型,求算2003～2013年青藏高原及邻域的现今重力变化图像,利用该趋势图像中若干特征点上的月重力变化数据,由最小二乘拟合其长期重力变化,验证重力变化图像的可靠性,最后简要探讨青藏高原重力变化的原因。结果显示,现今青藏高原及邻域未呈现整体尺度的重力变化趋势; 近年来青藏高原强震主要发生在重力变化呈现明显四象限分布特征的大型断裂带上; 相对于地壳均衡效应不明显的青藏高原东缘地区,高原腹地的地壳均衡效应更加显著。

Based on the GRACE monthly gravity models from 2003 to 2013,we first indicated the long-term gravity change pattern of Tibet plateau and its adjacent areas.Then we studied the monthly gravity variation data of eight feature points in gravity variation tendency graphy and fitted its long period gravity variation by the least squares method,which validated the reliability of the gravity change pattern.Finally the possible reasons for the gravity change were discussed in Tibet plateau and its adjacent areas.The result shows as follows:The nowadays gravity change does not show a whole-level pattern in Tibet plateau and its adjacent areas.The strong earthquakes for these years broke out on the big faults where the gravity change presented four-quadrant distribution pattern.The crustal isostatic effect in central Tibet plateau is more significant comparing to that of eastern Tibet plateau.

引言
1 数据与方法
2 GRACE反映的青藏高原现今重力变化
3 青藏高原及邻域现今Moho起伏特征
4 结论

图1 2003～2013年青藏高原及邻域卫星重力年变化率图像<br/>Fig.1 Annual variation rate of satellite gravity in Tibet plateau and its adjacent area from 2003 to 2013

图1 2003～2013年青藏高原及邻域卫星重力年变化率图像
Fig.1 Annual variation rate of satellite gravity in Tibet plateau and its adjacent area from 2003 to 2013

图2 8个重力变化特征点上的月重力变化特征及拟合曲线(单位:μGal)<br/>Fig.2 Monthly gravity change and its fitted curve of eight gravity change feature points(unit:μGal)

图2 8个重力变化特征点上的月重力变化特征及拟合曲线(单位:μGal)
Fig.2 Monthly gravity change and its fitted curve of eight gravity change feature points(unit:μGal)

表1 图1中特征点上一维拟合斜率<br/>Tab.1 The one-dimensional fitting slopes of eight gravity change feature points in Fig.1

表1 图1中特征点上一维拟合斜率
Tab.1 The one-dimensional fitting slopes of eight gravity change feature points in Fig.1

图3 青藏高原及邻域Moho面年变化率<br/>Fig.3 The gravity annual change of Moho in Tibet Plateau and its adjacent area

图3 青藏高原及邻域Moho面年变化率
Fig.3 The gravity annual change of Moho in Tibet Plateau and its adjacent area

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备注

引言

1 数据与方法

2 GRACE反映的青藏高原现今重力变化

3 青藏高原及邻域现今Moho起伏特征

4 结论

期刊信息