基于深地震测深的深部动力学研究方法和应用     

宋向辉  田晓峰  刘少峰  王帅军  杨宇东 《地质论评》2021,67(1):193-208

深地震测深是探测壳幔岩石圈精细速度结构、探讨岩石圈变形和演化过程的一种有效方法,在青藏高原隆升、克拉通裂解等大陆动力学研究中已发挥了重要的作用.然而,地震测深方法与深部动力学研究的结合尚处于现象描述为主的状态.因此,本文对前人利用深地震测深资料进行深部动力学研究的相关方法进行了回顾与总结:宽角反射/折射地震震相特征具有...  相似文献   

Thermal activation of current in an inhomogeneous Schottky diode with a Gaussian distribution of barrier height     

茹国平  俞融  蒋玉龙  阮刚 《海洋学报(英文版)》2010,29(9)

This paper investigates the thermal activation behaviour of current in an inhomogeneous Schottky diode with a Gaussian distribution of barrier height by numerical simulation. The analytical Gaussian distribution model predicted that the I--V--T curves may intersect with the possibility of the negative thermal activation of current, but may be contradictory to the thermionic emission mechanism in a Schottky diode. It shows that the cause of the unphysical phenomenon is related to the incorrect calculation of current across very low barriers. It proposes that junction voltage V_j, excluding the voltage drop across series resistance from the external bias, is a crucial parameter for correct calculation of the current across very low barriers. For correctly employing the thermionic emission model, V_j needs to be smaller than the barrier height Ф. With proper scheme of series resistance connection where the condition of V_j > Ф is guaranteed, I--V--T curves of an inhomogeneous Schottky diode with a Gaussian distribution of barrier height have been simulated, which demonstrate normal thermal activation. Although the calculated results exclude the intersecting possibility of I--V--T curves with an assumption of temperature-independent series resistance, it shows that the intersecting is possible when the series resistance has a positive temperature coefficient. Finally, the comparison of our numerical and analytical results indicates that the analytical Gaussian distribution model is valid and accurate in analysing I--V--T curves only for small barrier height inhomogeneity.  相似文献   

腾冲地区近震S波分裂研究          下载免费PDF全文

王雪鹤  李永华  呼楠 《地球物理学报》2021,64(1):131-145

本文利用布设在云南腾冲地区的15个固定和流动地震台站记录的近震波形数据,采用剪切波分裂分析方法得到了593对高质量的各向异性分裂参数.结果显示,腾冲火山区地震台站下方的近震各向异性的慢波延迟时间为0.02?0.37 s,平均延迟时间0.2 s.结合已有接收函数地壳各向异性研究结果,推测研究区地壳各向异性的主要贡献源自中...  相似文献   

乌鲁木齐市区断层附近原地应力测量研究   总被引：3，自引：0，他引：3  

李宏  谢富仁  刘凤秋  董建业  孙启伟 《地震地质》2007,29(4):805-812

利用水压致裂原地应力测试技术,在乌鲁木齐市区碗窑沟断裂东段、雅玛里克断裂东段和西山断裂带中、东段开展了断层附近原地应力测量研究,得到了地表浅部构造应力的大小、方向和分布特征。钻孔HFZK3位于碗窑沟断裂东段的南侧,孔深62.13m;钻孔HFZK5位于雅玛里克断裂东段的南侧,孔深30.00m;钻孔HFZK9和HFZK12都位于西山断裂带的中、东段,孔深分别为34m和54.5m。根据实测的地应力资料,断层附近最大水平主压应力方向为NE—NEE向,与区域构造应力SN—NNE向主压方向有一些差异,说明受断层活动影响,断层附近的应力状态与区域应力场明显不同。利用地应力实测资料研究了断层的活动性,在测量深度域内水平和垂直应力的关系为σH>σh>σV,该应力状态有利于逆断层活动,与地质资料反映的以逆断层活动为主基本一致。利用库仑摩擦滑动准则,摩擦强度取0.6～1.0进行分析,断层附近的现今地应力状态达到或超过产生逆断层摩擦滑动的临界值,表明测区现今构造活动以逆断层为主。研究区的3条断层不具备发生走滑断层活动的可能性,其中雅玛里克断裂东段、西山断裂带中段和东段具有发生逆断层活动的可能性,相比而言,西山断裂带中段危险性更大  相似文献   

Evaluation of vertical crustal movements and sea level changes around Greenland from GPS and tide gauge observations     

Jiachun An  Baojun Zhang  Songtao Ai  Zemin Wang  Yu Feng 《海洋学报(英文版)》2021,40(1):4-12

To better monitor the vertical crustal movements and sea level changes around Greenland, multiple data sources were used in this paper, including global positioning system(GPS), tide gauge, satellite gravimetry, satellite altimetry, glacial isostatic adjustment(GIA). First, the observations of more than 50 GPS stations from the international GNSS service(IGS) and Greenland network(GNET) in 2007–2018 were processed and the common mode error(CME) was eliminated with using the principal component analysis(PCA). The results show that all GPS stations show an uplift trend and the stations in southern Greenland have a higher vertical speed. Second, by deducting the influence of GIA, the impact of current Gr IS mass changes on GPS stations was analysed, and the GIA-corrected vertical velocity of the GPS is in good agreement with the vertical velocity obtained by gravity recovery and climate experiment(GRACE). Third, the absolute sea level change around Greenland at 4 gauge stations was obtained by combining relative sea level derived from tide gauge observations and crustal uplift rates derived from GPS observations, and was validated by sea level products of satellite altimetry. The results show that although the mass loss of Gr IS can cause considerable global sea level rise, eustatic movements along the coasts of Greenland are quite complex under different mechanisms of sea level changes.  相似文献   

基于接收函数的华南及邻区地壳结构研究     

查小惠  吕坚  江春亮  汤兰荣  董非非  鲍志诚  童琼 《大地测量与地球动力学》2021,41(1):67-73

利用华南地块及邻区2007～2012年609个地震台站记录的约900个5.7级以上远震事件,获得各台站的接收函数,通过分析接收函数的形态变化了解各台站下方的地壳结构特征,然后再利用H-κ叠加搜索技术获得各台站下方的地壳厚度和波速比.结果显示,研究区的地壳结构表现为从沿海向内陆逐渐复杂的变化,地壳厚度也表现出由沿海向内陆...  相似文献   

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崔笃信  王庆良  王文萍 《大地测量与地球动力学》2008,28(3):1-8

????????????丽???????????α?????????????????,??Okada??????????????????????2001??11??14??????8.1??????????λ????????????α??????????????????1??????8.1???????????????????????????????????????λ??????????????40 mm?????2??????????????????????GPS?????????????????????????????????????????  相似文献   

大气负荷对兰新铁路线区域地壳形变及重力变化的影响     

张波  杨国林  孙学先  刘涛  安旭伟 《大地测量与地球动力学》2021,41(5):497-500

使用兰新铁路线周边区域2012～2017年的全球大气模型和区域气象站气压数据,根据大气负荷理论,采用移去-恢复法计算该区域在6 a间大气负荷对地壳形变和重力变化的影响.结果 显示,大气负荷对兰新线区域的垂直形变影响为1 cm左右,对水平形变影响小于2 mm,对垂线偏差影响约为6 ms,对地面重力影响大致为6 μGal;...  相似文献   

大别山晓天—磨子潭断裂附近退变榴辉岩的厘定及其时代和大地构造意义     

刘琦  刘贻灿  杨阳 《地质论评》2024,70(S1):5-6

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A Seismic Investigation of the Kenya Rift Valley     

W. J. Henry  J. Mechie  P. K. H. Maguire  M. A. Khan  C. Prodehl  G. R. Keller  J. Patel 《Geophysical Journal International》1990,100(1):107-130

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