Pacific Ocean width at about 5°N latitude, where it stretches approximately from Indonesia to the coast of Colombia—halfway around the world, and more than five times the diameter of the Moon. The lowest known point on Earth—the Mariana Trench—lies below sea level. Its average depth is , putting the total water volume at roughly . Due to the effects of plate tectonics, the Pacific Ocean is currently shrinking by roughly per year on three sides, roughly averaging a year. By contrast, the Atlantic Ocean is increasing in size. Along the Pacific Ocean's irregular western margins lie many seas, the largest of which
Group on Earth Observations Group on Earth Observations The Group on Earth Observations (or GEO) coordinates international efforts to build a Global Earth Observation System of Systems (GEOSS). It links existing and planned Earth observation systems and supports the development of new ones in cases of perceived gaps in the supply of environment-related information. It aims to construct a global public infrastructure for Earth observations consisting in a flexible and distributed network of systems and content providers. Common Earth observation instruments include ocean buoys, meteorological stations and balloons, seismic and Global Positioning System (GPS) stations, remote-sensing satellites, computerized forecasting models and early warning systems.