摘要
以层状地层中多个位于不同位置和不同埋深的三维导电薄板为例,对瞬变电磁(TEM)法分辨地下多个三维异常体的能力进行了详细的分析和讨论。模型计算的结果表明,无论异常体与源的距离远近,TEM法对近地表的多个异常体分辨能力总是很好。当多个异常体在垂直方向排列时,TEM法对它们的探测能力最差;当它们以不同埋深沿测线方向排列时,埋深最浅和最近源的异常体最容易探测到;当夹在中间的异常体规模较小、埋深较大时,它的异常场容易被其它异常体所掩盖。总体上讲,无论在源下方还是在接收器下方,TEM法对水平方向多个异常体分辨能力优于垂向上的。
In this paper, the detectability of the transient electromagnetic (TEM) method to multiple anomalous bodies with different locations and buried depths in the stratum was detailed discussed. The results of these models illustrate that the detectability of TEM to those bodies buried shallower is quite good no matter whatever their distance from the source, which also gives a further theoretical basis to the idea that TEM method can be used in the shallow target exploration. The detectability is the poorest when the multiple thin bodies are arranged vertically. When those anomalous bodies which have different locations and depths are horizontally arranged along the measurement line, those bodies with shallower depths and the one which is nearest to the source can be most easily detected by TEM method, while the bodies between them are always neglected if their sizes are too small or depth are too large. In general, the detectability of TEM to multiple bodies is much better to those arranged horizontally than those arranged vertically.
出处
《物探与化探》
CAS
CSCD
2004年第6期528-531,共4页
Geophysical and Geochemical Exploration
关键词
三维模型
正演
瞬变电磁响应
多个异常体
埋深
探测能力
3D models
forward modeling
transient electromagnetic responses
multiple anomalous bodies
buried depth
detectability
