Gravity observations along the eastern margin of the Tibetan Plateau and an application to the Lushan Ms7.0 earthquake     

Wei-feng Liang  Yun-feng Zhao  Yun-ma Xu  Yi-qing Zhu  Shu-song Guo  Fang Liu  Lian Liu 《地震学报(英文版)》2013,(3):251-257

This paper introduces relative and absolute gravity change observations in the eastern portion of the Tibetan Plateau. We analyze and discuss a change that occurred in 2010 in the gravity along the eastern margin of the plateau and the relationship between this change and the 2013 Lushan Ms7.0 earthquake. Our results show that： （1） before the Lushan MsT.0 earthquake, gravity anomalies along the eastern margin of the Tibetan Plateau changed drastically. The Lushan earthquake occurred at the bend of the high gradient zone of gravity var- iation along the southern edge of the Longmenshan fault zone. （2） The 2013 Lushan earthquake occurred less than 100 km away from the epicenter of the 2008 Wenchuan earthquake. Lushan and Wenchuan are located at the center of a four- quadrant section with different gravity anomalies, which may suggest that restoration after the Wenchuan earthquake may have played a role in causing the Lushan earthquake. （3） A medium-term prediction based on changes in gravity anoma- lies was made before the Lushan Ms7.0 earthquake, in par- ticular, a prediction of epicenter location.  相似文献   

AS350-B3型直升机硬架航空磁测系统在青藏高原上的应用     

许苏鹏  姬泰脉  纪福山  张贵宾  杨望 《物探与化探》2013,(4)

为适应在青藏高原高海拔山区开展大比例尺低空航空物探测量工作,满足低飞行高度、高测量精度的要求,通过对比其他机型在机场条件、起飞升限、最大升限、高原机动性能,首次选择使用AS350-B3型直升机并设计制作长杆硬架防振航空磁测系统。对该机型在地面及空中试验进行了磁干扰形式、周期、幅值及衰减规律测试,发现其磁干扰主要由周期为96s幅值约为700nT的脉冲磁干扰、幅值约为300nT的方波磁干扰和周期为1s幅值约为20 nT由螺旋桨转动引起的磁干扰杂波组成,通过把磁探头适当远离飞机发动机及螺旋桨,对硬架系统加装防振部件,再加上磁测设备中的软补偿系统的磁补偿,就可能较好地克服飞机动作及振动引起的磁干扰,从而测量到高质量的磁数据,满足了在高海拔地形切割较大地区作业的要求。  相似文献