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Panthalassa, also known as the Panthalassic or Panthalassan Ocean, (from Greek Ïá¾¶Î½ all and Î¸Î¬Î»Î±ÏÏÎ± sea), was the superocean that surrounded the supercontinent Pangaea. During the PaleozoicâMesozoic transition c. 250 Ma it occupied almost 70% of Earth's surface.
In terms of geography, a sea is part of the ocean partially enclosed by land. Seas are found on the margins of the ocean and are partially enclosed by land. Here, you can see that the Bering Sea is part of the Pacific Ocean. Many people use the terms ocean and sea interchangeably when speaking about the ocean, but there is a difference between the two terms when speaking of geography (the study of the Earth's surface). Seas are smaller than oceans and are usually located where the land and ocean meet.