World Ocean that covers and encircles most of Earth. If viewed from the southern pole of Earth, the Atlantic, Indian, and Pacific Oceans can be seen as lobes extending northward from the Southern Ocean. Farther north, the Atlantic opens into the Arctic Ocean, which is connected to the Pacific by the Bering Strait, forming a continuous expanse of water. Plate tectonics, post-glacial rebound, and sea level rise continually change the coastline and structure of the world ocean. World Ocean The World Ocean or Global Ocean (colloquially the sea or the ocean) is the interconnected system of Earth's oceanic waters, and comprises the
Ocean Observatories Initiative the ocean from physical, chemical and biological perspectives. Lithospheric movements and interactions at plate boundaries at or beneath the seafloor are responsible for short-term events such as earthquakes, tsunamis and volcanic eruptions. These regions are also host to the densest hydrothermal and biological activity in the ocean basins. The oceanic crust contains the largest aquifer on Earth. Thermal circulation and reactivity of seawater-derived fluids can modify the composition of oceanic plates, lead to the formation of hydrothermal vents that support unique micro- and macro-biological communities and concentrate methane to form massive methane gas and methane hydrate reservoirs. The four main