Table of Contents
- 1 Why do geologists drill through the oceanic crust in their attempt to reach the mantle?
- 2 Why continental crust does not sink into the mantle yet oceanic crust does?
- 3 What’s the deepest hole ever dug in the Earth?
- 4 Why does the oceanic plate sink?
- 5 What is difference between oceanic crust and continental crust Why do we care about what type of crust covers a tectonic plate?
Why do geologists drill through the oceanic crust in their attempt to reach the mantle?
Due to its unique geology, the ocean is relatively shallow in this area and the mantle rises close to the surface, making it easier to access. It also means there are less hard-to-crack crustal rocks, which have thwarted previous attempts to access this part of the Earth’s crust.
Why continental crust does not sink into the mantle yet oceanic crust does?
Both oceanic and continental crusts are generally less dense than the asthenosphere, so most oceanic and continental crusts “float” on the asthenosphere. Because ocean crust is more dense than continental crust, it will sink beneath continents if tectonic forces push the oceanic crust into the continent.
What is the difference between the oceanic and continental crust and why is the oceanic crust submerged under the ocean?
Magma shoots up through gaps in the ocean’s floor here. As it cools, it hardens into new rock, which forms brand new segments of oceanic crust. Since oceanic crust is heavier than continental crust, it is constantly sinking and moving under continental crust.
What happens when oceanic crust subducts beneath continental crust?
When oceanic crust converges with continental crust, the denser oceanic plate plunges beneath the continental plate. This process, called subduction, occurs at the oceanic trenches. The subducting plate causes melting in the mantle above the plate. The magma rises and erupts, creating volcanoes.
What’s the deepest hole ever dug in the Earth?
The deepest hole by far is one on the Kola Peninsula in Russia near Murmansk, referred to as the “Kola well.” It was drilled for research purposes beginning in 1970. After five years, the Kola well had reached 7km (about 23,000ft).
Why does the oceanic plate sink?
An oceanic plate will sink back into the mantle. Young oceanic lithosphere is hot and buoyant (low density) when it forms at a midocean ridge. But as it spreads away from the ridge and cools and contracts (becomse denser) it is able to sink into the hotter underlying mantle.
Why does the continental crust float on top of the oceanic crust?
It is less dense than the material of the Earth’s mantle and thus “floats” on top of it. Continental crust is also less dense than oceanic crust, though it is considerably thicker; mostly 35 to 40 km versus the average oceanic thickness of around 7-10 km.
What are the main differences between oceanic crust and continental crust?
The oceanic crust is mainly made out of dark basalt rocks that are rich in minerals and substances like silicon and magnesium. By contrast, the continental crust is made up of light-colored granite rocks full of substances like oxygen and silicon.
What is difference between oceanic crust and continental crust Why do we care about what type of crust covers a tectonic plate?
It is the solid rock layer upon which we live. It is either continental or oceanic. Continental crust is typically 30-50 km thick, whilst oceanic crust is only 5-10 km thick. Oceanic crust is denser, can be subducted and is constantly being destroyed and replaced at plate boundaries.