The Pacific Ocean shrinks by about 2 to 3 centimeters every year.

The Pacific Ocean sits on the Pacific Plate. This plate is surrounded by the Ring of Fire, which is a series of subduction zones. At these zones, the edges of the ocean floor slide under continental plates and melt into the Earth's mantle.Data from the National Oceanic and Atmospheric Administration shows this happens along the coasts of Asia and the Americas. While the Pacific shrinks, the Atlantic Ocean is actually growing wider. This happens at the Mid-Atlantic Ridge where magma rises to create new seafloor. The Atlantic grows by about 2.5 to 4 centimeters each year.This cycle of oceans opening and closing is called the Wilson Cycle. Researchers at Curtin University used supercomputers to track these movements over millions of years. They predict that the Pacific Ocean will eventually disappear completely. This will happen when the Americas and Asia collide to form a new supercontinent called Amasia. This event is expected to occur in 200 to 300 million years.