Around 70% of the Earth’s surface is covered by oceans. Thus the crests mark constructive plate boundaries where the Earth's lithospheric plates are moving apart.As a result of this separation, hot material from the asthenosphere (the layer below the lithosphere, itself comprised of the crust and the top part of the mantle) wells up at the ridge crests and partly melts to form pockets of magma. Is ocean floor smooth? The molten material may then slowly crystallize in the lower crust, or it may rise to the middle of the crust and solidify in fissures (thereby forming dykes) or it may be extruded as lava onto the ocean floor.As sea-floor spreading continues, newly-created crust moves away from the mid-ocean ridge crest and gradually becomes cooler, thicker and denser, with the result that it subsides.Geologists have discovered that the amount by which the oceanic crust subsides is related to its age only (if the crust is not overlain with - and therefore depressed by - sediments).
These are a lot like the lakes we know, in that … In fact, it has been said that we know more about the surface of the moon than about the deeper ocean trenches. The ocean is three percent salt. The magma is lighter (of lower density) than the surrounding mantle and therefore rises into the relatively thin crustal layer. New oceanic crust is created at the ridge crests by sea-floor spreading. Others are submerged but are flat on top (in which case they are called guyots) or have coral atolls associated with them - evidence that they previously protruded above the sea.The submergence of an oceanic volcano indicates that it was formed in relatively shallow water near an active ridge crest but has since been moved into deeper water (as a result of movement of the plate on which it stands) away from the active area (called a "hot spot"). Now we know that the deep oceans have features such as mountains, deep valleys, and vast plains.
Consisting of a narrow, continuous belt of submarine mountains, each ocean ridge extends along virtually the entire length of its ocean.The crests of the ridges rise to within 2 to 3km of the sea surface. Just a century ago, the ocean floor was largely unknown. Here are 15 crazy facts about the ocean floor. Convection currents in the molten mantle cause the plates to slowly move about the Earth a few centimeters each year. Volcanic activity associated with mid-ocean ridges and subduction zones creates many of the most striking and interesting features of the ocean floor. Continental Shelf. We know very little about the deep ocean floor and the life it holds due to the depth and the difficulties this creates for scientists. These fractures cut across mid-ocean ridges, usually offsetting the ridge crests.The fractures on the slowly-spreading ridges of the Atlantic and Indian oceans tend to be closer together and to cause less offsetting than those of the faster-spreading Pacific ridges.Fracture zones are seismically inactive along most of their lengths but represent the sites of previous active transform faulting (faulting caused by sideways plate movements).Most of the remaining features of the ocean floor result from large outpourings of magma, which typically form submarine volcanoes.
The largest ocean on Earth is the Pacific Ocean, covering around 30% of the Earth’s surface. Take a deep breath, gang, as we dive into our ocean facts! The name “Pacific Ocean” comes form the Latin name Tepre Pacificum, “peaceful sea”. The lack of weathering and erosion in most areas, however, allows geological processes to be seen more clearly on the seafloor than… The ocean floor covers 70% of the Earth’s surface.
)The ocean basins are characterized not only by lying in deep water (the ocean floor averages about 4km below sea level) but also by being underlain by a thin layer of crust; on average, oceanic crust is only 6 to 7km thick, compared to 35 to 40km for continental crust.The crests of the ridges rise to within 2 to 3km of the sea surface. It is estimated that only about five percent of the world’s oceans have been totally explored. The outer rocky layer of the Earth includes about a dozen large sections called tectonic plates that are arranged like a spherical jig-saw puzzle floating on top of the Earth's hot flowing mantle.
About three-quarters of our planet's surface is covered with water and the deep basins of the ocean floor account for approximately nine-tenths of this water-covered area - that is, some two-thirds of the Earth's surface. The mid-ocean ridges are the most extensive features of the Earth's surface. Occasionally so much magma is extruded that a rise or plateau with unusually thick crust forms; perhaps the most conspicuous example is the Icelandic Plateau, which protrudes above sea level.Some marine volcanoes also rise above the sea surface, forming volcanic islands. If Mount Everest was placed in the deepest part of the ocean, its peak would be covered by over 7000 feet of seawater. Here are 15 crazy facts about the ocean floor.Greentumble was founded in the summer of 2015 by us, Greentumble is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.