Spatial Distribution of Contourites in Global Ocean and Its Paleoclimatic Significance—The Contribution of International Ocean Drilling to the Studies of Contourites

Contourite is one of the most important type of sediments in the global ocean, which has recorded significant information on paleoclimatic changes. It is also of great importance for ocean engineering and marine hydrocarbon exploration. The development of scientific ocean drilling, especially the “Integrated Ocean Drilling Program” and the undergoing “International Ocean Discovery Program”, has made great contribution in mapping the spatial distribution of contourites and revealing contourite-related paleoclimatic information, through coring and geophysical exploration in the global ocean. It is found that the global distribution of contourites is controlled predominantly by the global deep-water circulation while its distribution in a specific region can be affected by the intensity of deep currents, tectonic activities, sediment supply, and so on. The geological changes in the global deep-water circulation is, however, further affected by tectonic activities, origins of water masses, as well as climate changes, e.g. the Cenozoic global cooling, changes in the size of the northern hemisphere ice caps, and intensity of monsoon. The main controlling factors of deep water circulation vary with different regions.     

2022年芦山6.1级地震和马尔康6.0级地震前的重力变化特征

地震孕育过程中的地表重力值会发生相应的变化, 利用四川地区2018年3月—2022年4月的流动重力观测数据得到重力场等值线变化图, 研究2022年芦山6.1级地震和马尔康6.0级地震前的重力变化特征。 结果表明: ① 芦山6.1级地震和马尔康6.0级地震震前约一年半左右进入重力变化显著时期; ② 芦山6.1级地震对马尔康6.0级地震的发生有促进作用; ③ 芦山6.1级地震和马尔康6.0级地震前震区重力变化等值线出现类似于四象限区域的分布特征, 显示该处应力高度集中; ④ 芦山6.1级地震和马尔康6.0级地震震中区处于0值线附近且0值线在此处转折弧度较大, 是构造带易发震的薄弱位置。     

数字化成图在水库库区地形图测绘中的应用

通过工程实例介绍了数字化成图技术在水库库区地形图测绘中的应用。该方法摒弃了传统人工成图作业方式，实现了测绘工作的数字化，大大缩短了成图周期，确保了成果质量。