Seismic imaging of solid/fluid structure below and ocean vertical mixing structure above the seafloor

在将海底地壳结构地震勘探资料应用于海洋声学结构成像的尝试中，我们得到了以下结果。1.发生在南海增生棱柱体中的极低频地震代表了非常缓慢的板块边界滑动以及涉及流体通过板块边界迁移的水力破裂。2.提出了几种从地震勘探数据中获取海洋结构图像的方法。3.分析了北海道、伊豆-小笠原洋脊的黑潮暖心环、M2内潮和黑潮锋面的信号。4.对M2内潮进行了详细的分析，发现了涌浪和临界层吸收的证据。5.数值模拟了重力内波背景场与潮汐内波的相互作用，计算了重力内波背景场与潮汐内波相互作用的耗散率。

In an attempt to apply seismic exploration data acquired for submarine crustal structures to imaging of ocean acoustic structure, we obtained the following results. 1.Very-low-frequency earthquakes occurring in the Nankai accretionary prism represent very slow plate-boundary slip as well as hydrofractures involving fluid migration through the plate boundary. 2.We proposed several methods to obtain improved images of ocean structure from seismic exploration data. 3.We analyzed data from off Hokkaido, off Izu-Bonin ridge to detect signals of the Kuroshio warm core rings, M2 internal tides and the Kuroshio front. 4.A detailed analysis was made for the M2 internal tides to find evidence of billows and critical layer absorption. 5.We made a numerical simulation of internal tidal waves interacting with the background field of internal gravity waves to estimate their dissipation rate.