Sea Floor Of The Earth

Basalt the once molten rock that makes up most new oceanic crust is a fairly magnetic substance and scientists began using magnetometers to measure the magnetism of the ocean floor in the 1950s what they discovered was that the magnetism of the ocean floor around.

Sea floor of the earth.

The smooth flat regions that make up 40 of the ocean floor are the abyssal plain. Mountains plains channels canyons exposed rocks and sediment covered areas. Exploration of the seafloor and the earth s crust. The scripps sea floor map has also been used to discover a new microplate in the indian ocean.

On average oceanic crust is only 6 to 7km thick compared to 35 to 40km for con tinental crust. The latest status of its seabed 2030 project was announced to coincide with world hydrography day. In the 1960s earth scientists developed the theory of plate tectonics. In the 1960s the past record of geomagnetic reversals of earth s magnetic field was noticed by observing magnetic stripe anomalies on the ocean floor.

9 10 this results in broadly evident stripes from which the past magnetic field polarity can be inferred from data gathered with a magnetometer towed on the sea surface or from an aircraft. The magnetism of mid ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century. On the basis of tharp s efforts and other new discoveries about the deep ocean floor hess postulated that molten material from earth s mantle continuously wells up along the crests of the mid ocean ridges that wind for nearly 80 000 km 50 000 miles through all the world s oceans. 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.

It is the only intergovernmental organisation with a mandate to map the entire ocean floor. The sea floor then drops off steeply along the continental slope the true edge of the continent. Look at figure 14 23. The google earth data right is clearly higher resolution than that version of the scripps map left.

Bathymetry the shape of the ocean floor is largely a result of a process called plate tectonics 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. The lack of weathering and erosion in most areas however allows geological processes to be seen more clearly on the seafloor than on land. This program traces the development of plate tectonics beginning with the contributions and methods of geologist alfred wegener. Sea floor spreading continental drift paleomagnetism and the primordial supercontinent pangaea are some of the topics covered.