Structure of the Earth Structure of the Earth The internal structure of the Earth is layered in spherical shells: an outer silicate solid crust, a highly viscous asthenosphere and mantle, a liquid outer core that is much less viscous than the mantle, and a solid inner core. Scientific understanding of the internal structure of the Earth is based on observations of topography and bathymetry, observations of rock in outcrop, samples brought to the surface from greater depths by volcanoes or volcanic activity, analysis of the seismic waves that pass through the Earth, measurements of the gravitational and magnetic fields of the Earth, and experiments
The Conflict Over the Sovereignty of the Diaoyu Islands -- between Taiwan (ROC), China (PRC), & Japan depth of the Okinawa trough that locates in the east is as deep as 2,717 meters, forming a natural sea boundary with China and the Ryukyu islands. As the geological structure of the Ryukyu Islands belong to "oceanic crust", the Diaoyu Islands are "continental crust" that makes a significant difference in between those two. Also, the Diaoyu Islands has one of the largest scale of continental reef layer that contains an abundant amount of river deposits such as the Yangtze River and the Yellow River, and is therefore potentially rich in oil. The Diaoyu islands are considerably much more strategic