Resistivity measurements on the sea bottom to map fracture zones in the bedrock underneath sediments1
Resistivity measurements on the sea bottom to map fracture zones in the bedrock underneath sediments1
复制标题
海底电阻率测量可绘制沉积物下方基岩的断裂带1
DOI：
10.1111/j.1365-2478.1994.tb00242.x
复制
发表时间：
1994
影响因子：
2.6
通讯作者：
J. E. Buan
中科院分区：
文献类型：
--
作者：
O. B. Lile;K. R. Backe;H. Elvebakk;J. E. Buan
在挪威，利用海底炮点和水听器电缆进行折射地震已成为建造海上隧道前调查岩石质量的标准地球物理方法。在挪威公共道路管理局建造海底隧道方面，进行了研究工作，以比较折射地震法和其他方法所显示的两个低速区。建造了一条用于海底极-偶极测量的特殊电阻率电缆，电极之间的距离为10米。一个200米长的剖面，跨越两个低速区，测量与所有组合的电极距离。这两个区域被检测为低电阻率区域。介绍了一种特殊的数据处理技术，以增强异常。讨论了在海水环境中探测海底沉积物下基岩断裂带的电阻率测深法。得出的结论是，严重的断裂带，这可能会导致隧道施工的困难，可以检测与海面和海底阵列使用长电极间距。
Refraction seismics with the shotpoints and the hydrophone cable on the sea-bottom, have become the standard geophysical method for investigating rock quality before constructing offshore tunnels in Norway. In connection with the construction of a sub-sea tunnel by the Norwegian Public Roads Administration, research work was carried out to compare two low-velocity zones, indicated by refraction seismics with other methods. A special resistivity cable for pole-dipole measurements on the sea-floor, with 10 m between the electrodes, was constructed. A 200 m long profile, crossing the two low-velocity zones, was measured with all combinations of electrode distances. The two zones were detected as low-resistivity zones. A special data processing technique to enhance the anomalies is described. Resistivity soundings in a seawater environment to detect fracture zones in the bedrock underneath the bottom sediments, are discussed. It is concluded that severely fractured zones, which may cause difficulties for the tunnel construction, can be detected both with sea-surface and sea-floor arrays using long electrode spacings.