西太平洋是地球上海底火山最密集的区域，其中沙茨基海隆拥有地球上最大的单体火山。本项目探索目前尚未解决的重要科学问题：沙茨基海隆的大火山形成后残留岩浆的喷发机制。项目拟聚焦以下核心研究内容：（1）利用50万平方公里的高精度多波束测深数据和6600公里的高分辨率多道地震剖面定量分析沙茨基海隆上266座次生海山的形态和结构；（2）借助11个大洋钻探岩芯数据约束海山的活动时期；（3）统计分析海隆区内海山的时空分布特征，验证是否受先存洋中脊和断裂带的控制；（4）对比全球类似构造的后期火山活动，最终揭示次生海山形成的主控因素。申请人已完成大量的前期观测，所在项目组具有海洋地球物理研究领域的长期积累。项目创新点在于首次定量并统计分析沙茨基海隆次生海山的形态、结构以及时空分布特征，系统性研究一座典型大火成岩省的残留岩浆喷发机制，对理解地幔过程在地表的表现形式以及认识地球岩石圈演化的基本规律都具有重要意义。

Underwater volcanoes are most developed in the Pacific Ocean, within which the Shatsky Rise is featured by the largest single volcano on Earth. After the main eruptions that formed the volcanic shield of the Shatsky Rise, the activity of remaining magma is nevertheless poorly studied. We propose to conduct quantitative analysis on the morphology and structure of hundreds of secondary seamounts over the surface of the Shatsky Rise using high quality multi-beam bathymetry data and high resolution multi-channel seismic profiles. The timing of the late-stage volcanism is constrained by ocean drilling core data. The temporal and spatial distribution of the seamounts will be subsequently obtained in a statistic way, which can test the well-accepted hypothesis that secondary volcanism is controlled by rifted zones of the mid-ocean ridges. Comparing with other thousands of seamounts in the global oceans, it is likely to show the mechanism of secondary seamount formation in a big picture. The practicability of this proposal is high because the applicant has been engaged in prior geophysical observations, and the working group has strong background of marine geophysics. The proposed study is original and significant due to the quantitative and statistic study of secondary seamounts, which can provide insight to the surface expressions of the poorly understood mantle process and the lithosphere evolution of the Earth.