A Method for Reducing Ocean Wave-Induced Magnetic Noises in Shallow-Water MT Data Using a Complex Adaptive Filter

In shallow-water areas, the marine magnetotelluric (MT) method faces a challenge in the investigation of seabed conductivity structures due to electrical and magnetic noises induced by ocean waves, which seriously contaminate MT data. Ocean waves can affect electric and magnetic fields to different extents. In general, their influence on magnetic fields is considerably greater than that on electric fields. In this paper, a complex adaptive filter is adopted to reduce wave-induced magnetic noises in the frequency domain. The processing results of synthetic and measured MT data indicate that the proposed method can effectively reduce wave-induced magnetic noises and provide reliable apparent resistivity and phase data.