Plate Boundaries
Tectonic plates move away from each other at what type of plate boundary?
Divergent Boundary
Describe the outer layer of the Earth
Hard, solid rock.
The plates move _______ per year.
0.5-2in per year
What 3 things were first used as evidence for the idea of plate movement?
Fossils, rocks/mountains, continents "fit" together.
Which type of rock is formed by the cementation and compaction of sediments?
Sedimentary Rock
Convergent boundary
Describe the asthenosphere.
Soft, plastic-like rock.
Do plates move gradually or suddenly?
Gradually.
What is the name of a place in the middle of a plate where there is volcanic activity?
hotspot
Which type of rock is formed when rock has intense heat and pressure applied within Earth's interior?
Metamorphic Rock
What two types of boundaries have both earthquakes AND volcanic activity?
Convergent & Divergent
What causes the plates to move?
Convection currents in the mantle.
a diagram that shows what the inside of something looks like
Cross section
What type of plate boundary is between the South American Plate and the African plate?
Divergent
Which type of rock is formed when magma reaches the surface of Earth and cools to form solid rock?
Igneous Rock
What percentage of all volcanoes (approximately) are located at the "ring of fire"?
about 75%
What are the large chunks of Earth's outer layer called?
Tectonic plates
A denser crust sinks below a less dense crust at a convergent boundary. This is called ____________.
Subduction
Order the layers of the Earth from inside moving outwards.
Core, Mantle, Crust
What type of wave is a light wave?
Electromagnatic Wave
At this type of plate boundary, there is no volcanic activity, just earthquakes.
Transform boundary
What landform forms when two plates move away from each other?
Mid-ocean ridge
something we observe to be similar over and over again
Pattern
About how long ago was Pangea a supercontinent?
250 million years
About how thick is Earth's crust?
Continental: 25–70 km (about 15–44 mi)
Oceanic: 5–10 km (3.1–6.2 mi)