SEDIS IV型短周期自浮式海底地震仪数据校正方法

利用15台SEDISIV型短周期自浮式海底地震仪在南海中、北部地壳深部结构调查中所获得的资料,探讨了海底地震仪数据校正的方法和校正后的效果,结果表明:使用该地震仪所获得的原始资料经过放炮时间、炮点坐标数据局部化、海底地震仪位置误差以及记录时间漂移4方面的校正后,数据更趋合理,误差显著降低。放炮时间的校正消除了时钟漂移和时间延迟的误差;炮点坐标数据局部化处理消除了炮点位置整体趋势性偏移的现象;试错法进行位置误差和记录时间的精细校正时,时间漂移的校正量值约为几个到十几个毫秒,位置校正的量值仅在几米到数百米之间,实测数据所绘曲线的形态和位置都与理论曲线十分吻合,可见校正后误差显著降低。     

国际合作INDEPTH项目横穿青藏高原的深部探测与综合研究

国际合作青藏高原与喜马拉雅深部剖面探测(INDEPTH)计划自1992年开展以来,圆满完成Ⅰ、Ⅱ、Ⅲ、3个阶段研究任务,揭示了喜马拉雅山和青藏高原腹地的地壳结构和深部构造,在同际核心期刊公开发表10多篇有重要影响的学术论文,受到国际地球科学界的高度评价.第四阶段计划是研究高原北部边缘,即东昆仑造山带和柴达木盆地的结构构造及其形成演化,并与南部喜马拉雅造山带加以对比.经过多次野外地质踏勘,选定剖面的工作路线,2007年各方正式签订协议,并共同开展了野外调查,圆满完成了横穿东昆仑造山带和柴达木盆地的100km垂直深反射地震、300 km广角地震反射以及59个宽频带天然地震台站的野外观测施工任务.中方项目组还在东昆仑南部厘定出渐新世晚期-中新世早期大型逆冲推覆构造系统,发现青藏高原渐新世晚期-中新世早期整体隆升的重要证据.2008年将继续天然地震观测,还将开展大地屯磁测深、重力、地质构造剖面观测和反射地震数据处理;2009~2010年将利用各类深部探测资料,综合研究青藏高原北部的地壳结构、岩石圈构造和深部过程.     

Relativistic isotropic stellar model in f(R,T) gravity with Durgapal- IV metric

In this work, a new static, non-singular, spherically symmetric fluid model has been obtained in the background of $f(R,T)$ gravity. Here we consider the isotropic metric potentials of Durgapal-IV (Durgapal, 1982) solution as input to handle the Einstein field equations in $f(R,T)$ environment. For different coupling parameter values of $\chi$, graphical representations of the physical parameters have been demonstrated to describe the analytical results more clearly. It should be highlighted that the results of General Relativity (GR) are given by $\chi =0$. With the use of both analytical discussion and graphical illustrations, a thorough comparison of our results with the GR outcomes is also covered. The numerical values of the various physical attributes have been given for various coupling parameter $\chi$ values in order to discuss the impact of this parameter. Here we apply our solution by considering the compact star candidate LMC X-4 (Rawls et al., 2011) with mass $=(1.04\pm 0.09)M_{\odot }$ and radius $=8.301_{-0.2}^{+0.2}$ km. respectively, to analyze both analytically and graphically. To confirm the physical acceptance of our model, we discuss certain physical properties of our obtained solution such as energy conditions, causality, hydrostatic equilibrium through a modified Tolman–Oppenheimer–Volkoff (TOV) conservation equation, pressure–density ratio, etc. Also, our solution is well-behaved and free from any singularity at the center. From our present study, it is observed that all of our obtained results fall within the physically admissible regime, indicating the viability of our model.