Drifting Continents
Sea-floor Spreading
The Theory of Plate Tectonics
Forces that shape Earth
Earthquakes
Volcanoes
Volcanic Land Forms
100
Traces of an ancient organism preserved in rock.
What is a fossil?
100
The process which adds more crust to the ocean floor.
What is sea-floor spreading?
100
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The point where two plates move apart from each other.
What is a divergent boundary?
100
The force that acts on rock or crust to change its shape or volume.
What is stress?
100
What are Earthquakes?
100
Volcanoes form mostly at these types of plate boundaries.
What are convergent boundaries?
100
These form when lava flows out gradually building wide, gently sloping mountains.
What are shield volcanoes?
200
The person who made the hypothesis which sparked the idea of Pangea.
Who is Alfred Wegener?
200
These form long chains of mountains that rise up from the ocean floor.
What are Mid-Ocean Ridges?
200
What is a convergent boundary?
200
When the crust is pulled apart, stretching the rock.
What is tension?
200
Waves that carry the energy of an Earthquake away from the focus.
What are seismic waves?
200
The type of eruption that has magma high in silica with trapped gases that build up pressure until it explodes with incredible force creating a pyroclastic flow, or an eruption that hurls out ash, cinders, and magma bombs.
What is explosive eruption?
200
A huge hole left by the collapse of a volcanic mountain.
What is a caldera?
300
The idea that the continents slowly moved away from each other.
What is continental drift?
300
This is a deep under-water canyon found at a subduction zone.
What is Deep-Ocean Trench?
300
What is a transform boundary?
300
When rock or crust is squeezed until it folds or breaks.
What is compression?
300
The point beneath Earth’s surface where rock under stress breaks to cause an Earthquake.
What is Focus?
300
The point where a volcano is formed in the middle of a plate instead of as a result of plates converging.
What is a hot spot?
300
This is a tall cone-shaped mountain in which layers of lava alternate with layers of ash.
What is a composite volcano?
400
The supercontinent that Wegener suggested occurred on Earth about 300 million years ago.
What is Pangea?
400
A technique that scientists use to map the ocean floor.
What is sonar?
400
A break in the Earth's crust.
What is a fault?
400
When two slabs of crust are pushed past each other in opposite directions.
What is shearing?
400
The point on the surface directly above the focus.
What is the Epicenter?
400
A volcano that is not active, but may become active.
What is a dormant volcano?
400
A mass of rock formed when a large body of magma cools inside the crust.
What is a batholith?
500
The movement of plates is largely driven by this force.
What is convection?
500
The processes which change the size and shape of the oceans.
What are sea-floor spreading and subduction?
500
When pieces of Earth's crust diverge on land.
What is a rift valley?
500
Landforms which are formed by compression.
What are mountain ranges, volcanic arcs, and ocean trenches?
500
Compression waves that travel through solids and liquids, compressing and expanding the material they pass through. The first waves to arrive at a seismic center.
What are Primary Waves (P Waves.)
500
This type of eruption is low in silica content, flows easily, and erupts quietly with gases bubbling out gently and lava oozing quietly.
What is a quiet eruption?
500
A fountain of water and steam that erupts from the ground when buildup of pressure is released.
What is a geyser?