See also continental drift a veritable legion of evidence supports the seafloor spreading hypothesis.
Characteristics of sea floor spreading sea floor spreading cartoon.
World war ii gave scientists the tools to find the mechanism for continental drift that had eluded wegener.
That is the time it takes for new rock to form at the mid ocean ridge move atoss the ocean and sink into a trench.
The concept of sea floor spreading.
He suggested that new sea floor forms at the oceanic ridges and spread outwards from the line of origin.
Wherever continents are bordered by deep sea trench systems as in the pacific ocean the ocean floor is plunged downward underthrusting the continents and ultimately reentering and dissolving in earth s mantle from which it had originated.
The red colors are the youngest parts of the seafloor where fresh new crust is formed as lava seeps up from the deep interior of the earth at spreading ridges as new crust forms at these spreading ridges older crust colored green in the diagram moves away from.
Seafloor spreading happens at the bottom of an ocean as tectonic plates move apart.
At ridges in the middle of oceans new oceanic crust is created.
The motivating force for seafloor spreading ridges is tectonic plate pull rather than magma pressure although there is typically significant magma activity at spreading ridges.
Due to this continuous seafloor spreading occurs and makes atlantic ocean floor to be connected to other continental crust making the ocean gets wider over the time.
Seafloor spreading is the continuous process of forming new igneous rock at midocean ridges by injection of magma that forms new seafloor.
The concept of seafloor spreading was put forward by h harry hess an american geologist.
For instance the atlantic ocean is believed to be expanding because of its few trenches.
Further he claimed that continents would be pushed aside by the same forces that cause the ocean to grow.
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.
The magnetism of mid ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century.
The process of subduction and sea floor spreading can change the size and shape of the oceans.
The process is continuous because forces cause opposite sides of the midocean ridge to constantly move apart making new room for the process to repeat.
The seafloor moves and carries continents with it.
Subduction and sea floor spreading are processes that could alter the size and form of the ocean.
Hess called this processsea floor spreading.
Because of these processes the ocean floor is renewed about every 200 million years.
