Which of the following ocean floor features is associated with trenches?
Which of the following ocean floor features is associated with trenches?
subduction zone
Which ocean floor feature is formed where the oceanic crust Subducts?
More rarely, ocean trenches can be formed when two plates carrying oceanic crust meet. The Mariana Trench, in the South Pacific Ocean, is formed as the mighty Pacific plate subducts beneath the smaller, less-dense Philippine plate.
What are the features of the ocean floor?
Other significant features of the ocean floor include aseismic ridges, abyssal hills, and seamounts and guyots. The basins also contain a variable amount of sedimentary fill that is thinnest on the ocean ridges and usually thickest near the continental margins.
What discovery about the ocean floor is associated with seafloor spreading?
If this idea is correct, alternating stripes of normal and reversed polarity should be arranged symmetrically about mid-ocean spreading centers. The discovery of such magnetic stripes provided powerful evidence that sea-floor spreading occurs. The age of the sea-floor also supports sea-floor spreading.
What are the three pieces of evidence for seafloor spreading?
Several types of evidence supported Hess’s theory of sea-floor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves.
What are the two evidence of seafloor spreading?
Abundant evidence supports the major contentions of the seafloor-spreading theory. First, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge.
What kind of rock is the seafloor made of?
igneous rock
Which process consumes and recycles oceanic crust?
Mid-ocean ridges are structurally weak zones in the ocean floor, and where magma rises to form new oceanic crust. This process, called seafloor spreading, has built the present system of mid-ocean ridges. Subduction zones are plate boundaries where old oceanic crust is recycled back into the mantle.
Is the oceanic crust thicker than the continental?
Continental crust is typically 40 km (25 miles) thick, while oceanic crust is much thinner, averaging about 6 km (4 miles) in thickness. The less-dense continental crust has greater buoyancy, causing it to float much higher in the mantle.
Why is continental crust is thicker than oceanic crust?
The continental crust is also less dense than oceanic crust, although it is considerably thicker. Because of its relative low density, continental crust is only rarely subducted or recycled back into the mantle (for instance, where continental crustal blocks collide and over thicken, causing deep melting).