Warm Eddy- is an area of water that is made up of warm water and is surrounded by areas of colder water. The north side of the Gulf Stream is a very popular place to find these types of eddies as they form when the water gets cut off from the main Gulf Stream current and just sits and spins in the colder water until it’s replaced by colder water.
Cold Eddy- is an area of water that is made up of colder water and is surrounded by areas of warmer water. The south side of the Gulf Stream is a very popular place to find these types of eddies as they form when the water gets cut off on the south side of the current and it will just sit and spin in the warmer waters until it sinks below the warmer waters.
Ridge- an area of elevated ocean floor that extends in great depths upward from the seafloor bottom. A very famous ridge is the Mid-Atlantic Ridge which is located in the Atlantic Ocean between North America and Europe.
Trench- is an area in the ocean were the floor is extended downwards towards the earth’s interior. The most famous trench occurs off the coast of Guam known as the deepest trench. There is another trench off the coast of Japan which after the large earthquake in Japan was responsible for sinking small portions of the country into the trench.