deep sea canyons
A valley underwater is called a submarine canyon. These can form through a variety of geological processes, such as erosion by underwater currents or the collapse of underwater sediment. Submarine canyons can be important habitats for a diverse range of marine life.
V-shaped valleys in the continental shelf and slope are called submarine canyons. These are deep, steep-sided valleys that cut across the continental margin and are often formed by underwater processes such as turbidity currents or erosion by underwater currents. Submarine canyons can be comparable in scale to canyons found on land.
The ocean floor does have underwater mountains called seamounts and undersea valleys known as trenches. These features are created by tectonic plate movements and volcanic activity on the ocean floor.
They are both giant holes in the ground. Trenches are found underwater and valleys are found on land.
This is known as an oceanic trench.
Submarine canyons. These are steep-sided valleys that cut into the continental slope and sometimes extend onto the continental shelf. Submarine canyons can be formed by various processes, including erosion from turbidity currents or underwater landslides.
An underwater bubble blower.
A large underwater area between continents is called a submarine canyon. These are deep, steep-sided valleys cut into the seafloor by turbidity currents, often connecting continental shelves to the deep ocean. They can be thousands of meters deep and hundreds of kilometers long.
The island of maui is covered with many valleys created from the underwater volcanoe when it erupted hundreds of years ago. It is called the valley island because if you were to fly over the island, the first feature you will notice are the multiple valley's covering the surface of the island. Compared to the other hawaiian islands(Kauai, Oahu, Lanai, molokai, Hawaii, etc.) Maui has the most valleys. So basically, Maui is valley island cause it is covered with valleys, though some are too small to be officially called a valley.
Areas of underwater ground are called seabeds or ocean floors.
The most well known would be the Hawaiian island mountain range caused by underwater volcanic activity. Underwater.
The peaks are called crests and the valleys are called troughs in a wave.