What do you call a vally in the ocean?

Did mount fuji explode or did lava flow? Do giant beach worms bite? What kinds of activities can be enjoyed on Lake Minnetonka? What is the biggest sea dwelling animal? Are there rattlesnakes at devils lake park? A boat heading north crosses a wide river with a speed of 10kmhr relative to water the river has a speed of 5kmhr due east what is the velocity of the boat w respect to a stationary ground observer? What is Gifford Pinchot's belief about our National Forests? Is the Antarctic ocean cold? Where are the dykes on the Detroit river? Why are deep sea vents a wonder of the world? How many deserts are in the Middle West? What part of the castle would get attacked first? How far is Pompano Beach to Orlando? What is a fresh water cave? What physical process is MOST often responsible for island formation in the Pacific Ocean? How does the water get from the Niagara River to the power plants? The west Indies are located in which sea? On which continent is the Bermuda triangle located? Why is the east coast of the US cool and the west coast of the UK warm? What rides should you go on at Six Flags magic mountain?