水下激发极化测深异常特征研究

利用有限单元法对水下激发极化测深进行数值模拟以研究其异常特征和适用条件.水下的电阻率测深和激电测深均可对水底地质体进行近距离探测，提高探测分辨率.而水底地形对视电阻率测深的影响很大.水底极化体有限元正演模拟的结果表明，水底地形对激发极化测深结果没有影响.采用水下激发极化法进行地质体探测是可行、有效的.通过计算不同水体和水底岩石电阻率对视极化率幅值的影响发现，水体电阻率是影响水下极化率测深的主要因素.由于海水的电阻率过低，观测视极化率异常微弱而不适合开展水下激电工作.

A study on anomaly features detected by subaqueous induced polarization sounding

Numerical modeling of subaqueous induced polarization sounding using the finite element method is discussed.Based on this,the anomaly features and the range of application of subaqueous induced polarization sounding are studied. Subaqueous DC resistivity and IP sounding can be used to detect geologic bodies in close quarters to improve the resolving power.But DC resistivity sounding is influenced by terrain of water-bottom.The results of numerical modeling of subaqueous induced polarization show that the topographic don't have influence on the section of IP sounding.Subaqueous sounding of induced polarization is feasible and useful to detect geologic bodies.Calculating large numbers of models,we found that the resistivity of water is the primary factor to subaqueous IP sounding.The resistivity of seawater is so low that IP sounding cannot be carried out in the subaqueous condition.