【摘要】 地震的发生往往伴随着能量的转换和物质的运移,物质运移最直接的体现是重力异常的变化。为了对比地震前后重力异常的变化,在垂直龙门山断裂带走向上布设了2条实测重力剖面,揭示物质的运移规律及地震发生的原因。布格重力异常在汶川地区升高了15×10-5 m/s2,而周围地区布格重力异常却减小了;说明汶川地区是应力集中区,且青藏高原物质在楔入龙门山时的通道是有一定范围的。通过地震前后均衡异常和上地幔物质引起异常的变化特征也可以得到上述结论,并能证明物质运移在上地幔也有发生的观点。其结果揭示了汶川爆发地震的原因以及地下物质的运移规律,并为地震的预报工作提供了基础性依据。更多还原

【Abstract】 The occurrence of earthquake often accompanies energy conversion and material migration,the change of gravity anomaly is the most direct manifestation of material migration.In order to compare the changes of gravity anomaly before and after the earthquake,we have laid two gravity profiles which are perpendicular to the Longmenshan fault zone to reveal the rule of material migration and the cause of earthquake.Bouguer gravity anomaly in Wenchuan area has risen 15×10-5m/s2,while in other parts has reduced;the result shows that the migration channel of material of Qinghai-Tibet Plateau wedging in the Longmenshan has a certain range.Through the variation characteristics of isostatic gravity anomaly and gravity anomaly caused by material of upper mantle before and after earthquake,we can also get the above conclusions,and prove that the material migration occurs in the upper mantle.The results reveal the reasons of the Wenchuan earthquake and the rule of the material migration underground,it also provides a basic foundation for earthquake prediction.更多还原