Composition of the Earth and Plate Tectonics
What do scientists use to measure the rate of tectonic plate movement?
GPS (Global Positioning System)
Why do scientists look to the ocean floor to research the mantle?
because it is deep and has trenches
the liquid layer of the core
inner core
the solid layer of the core
inner core
what element makes up most of the Earth's core?
iron
the outermost, rocky layer of the Earth
lithosphere
three types of convergent boundaries
oceanic-oceanic, oceanic-continental, continental-continental
Density changes in the asthenosphere are caused by the flow of __________ energy from deep within the Earth.
thermal
boundary formed when tectonic plates slide past each other
transform boundary
What type of boundary produces earthquakes?
all of them (but mostly transform boundaries)
the "plastic" layer of the slow flowing rock in the mantle
asthenosphere
What causes tectonic plates to move?
convection currents in the mantle
boundary formed when tectonic plates collide
convergent boundary
three layers of the earth, based on their composition
crust, mantle, core
Mid-ocean ridges are the most common form of _____________ boundaries.
divergent boundaries
boundary formed when tectonic plates separate
divergent boundary
oceanic crust is denser than the continental crust because it contains more of which three elements?
iron, calcium, magnesium
the mantle contains more of the element _________ than the crust
magnesium
the strong, lower part of the mantle
mesosphere
What can form when 2 continental plates collide?
mountains
What are the 2 types of crust that a tectonic plate may contain?
oceanic (denser), continental (thicker)
three elements that make up most of the earth's crust
oxygen, silicon, aluminum
What is it called when two oceanic plates move apart and new crust is formed?
sea floor spreading (rising magma creates a new ocean floor)
What boundary is created during continental-oceanic crust collisions?
subduction zone
What are the large pieces of lithosphere that float on the asthenosphere called?
tectonic plates
How much of the Earth's mass is made up by the core?
1/3 (one third)
The theory that Earth is divided into plates that move around is called ...?
Plate Tectonics
