EARTH'S LAYERS
True or False: Earth is one solid slab of rock.
What is false?
A continuous underwater mountain range.
What is a mid-ocean ridge?
Long, narrow, cliff-like depression on the seafloor.
What is a deep-ocean trench?
Where crust slides past each other, and is neither created nor destroyed.
What are transform boundaries?
A device used to map the ocean floor, that bounces sound waves off underwater objects and records the echoes of these sounds.
What is sonar?
This material makes up the composition of the dense oceanic crust.
What is basalt?
The process that produces new oceanic crust at mid-ocean ridges.
What is seafloor spreading?
The process in which one plate is forced down into the mantle.
What is subduction?
Two plates pulling away from each other where new crust is created.
What are divergent plate boundaries?
The first feature formed when two lithospheric continental plates diverge.
What is rift valley?
The outermost layer of Earth and the upper mantle broken into irregularly shaped slabs.
What are Earth's lithospheric plates?
Mid-ocean ridges occur at this type of plate boundary.
What is a divergent boundary?
The factor that determines which plate sinks back into the mantle and which plate rises up on top.
What is density?
Two plates coming together where Earth's crust is destroyed.
What are convergent plate boundaries?
Evidence that you cannot touch or see directly. Pieced together through different information, so that inferences can be made. Seismic waves are one example.
What is indirect evidence?
The layer of "plastic rock" in which the lithospheric plates float.
What is the asthenosphere?
This substance cools down magma and forms rock.
What is water?
Five characteristics of oceanic crust near the deep-ocean trenches.
What is older, colder, denser, smoother, thicker?
Where earthquakes and deep-ocean trenches occur?
What are convergent boundaries?
The reason why other geologists doubted Wegener's theory.
What is 'the force (or mechanism)' that causes continental drift?
Created by movements in the liquid outer core.
What is Earth's magnetic field?
Symmetrical bands with magnetic properties, that overtime show reversals of mineral alignment with the poles.
What do the "zebra stripes" on the ocean floor represent?
A curved chain of volcanoes in the overriding tectonic plate of a subduction zone.
What is an island arc (or volcanic arc)?
One location creates new ocean floor while the other location recycles it.
What is the difference between mid-ocean ridges and subduction zones?
The two processes that cause the continents to 'drift'.
What is seafloor spreading and subduction?