摘要
为适应大地电磁拟地震解释法进一步发展的需要,本文提出了一种近似计算大地电磁场在一维地电模型中平均速度的方法。首先,将大地电磁的响应函数C(ω)化为部分分式,然后再把部分分式展成连分式,并把它与C(ω)的近似的连分式形式的解析表达式进行对比,从而求取平均速度。文中列出了各种理论模型和一条实测资料的计算结果,并对这条实测资料用文中所提方法画出了深度剖面。与地震反射法结果相比,这种方法比常规的大地电磁法和电测深法的结果要好。奥秘的大自然虽然千姿百态,但是,研究各种极不相同的自然现象的途径和方法,有时却有着相似和共同之处。某些学科成功的秘诀,常常给人以极其深刻的启示和教益,可供其他学科参考和借鉴。近几十年来,在地球物理勘探方法中,地震勘探的成功引人注目。把地震勘探中那些卓有成效的工作方法和解释方法有选择地运用到其他物探方法中来,已引起了越来越多的地球物理学家的兴趣和注意。大地电磁拟地震解释法把大地电磁测深法和地震反射法联系起来,在这方面已经有了一个良好的开端,迈出了可喜的一步。大家知道,可以比较准确地求得地震波在地层中的传播速度,是地震勘探得以成功的关键之一。
Abstract
In order to suit the needs of further development of the magnetotel-luric interpretation simulating seismic method, an approximate calculation of the average velocity of magnetotelluric field in 1-D magnetotel-luric model is suggested. In the first place, to transform the magnetotelluric response function C(ω) into partial fraction and then develop to a continued fraction and compare it with the analytic expression of C(ω) approximate continued fraction thus it enables us to determine the average velocity. Listed in the paper is the computing result from miscellaneous theoretical models and the measured data. Moreover, a depth section for the real data is plotted with the approach just brought up with which compare the result of seismic reflection. It proves that the mothod mentioned above could yield better result as compared with the magnetotelluric and electric sounding method.
论文详情