Earth's plates move very slowly across Earth's surface on a thin layer of the partly melted ___________
What is the mantle?
100
The point on Earth's surface right above the focus of an earthquake.
What is the Epicenter?
200
Continent-sized slabs that make up the crust and upper mantle.
What are plates?
200
A rocky opening in a volcano through which lava flows. Many are seen at the sides.
What is the vent?
200
Scientists use the Mercalli scale, the Richter Scale, and a seismograph to do this when there is an earthquake.
What is measure earthquakes?
200
Some volcanoes form new ___________ as plates move apart and magma rises to the surface of the crust.
What is ocean floor?
200
The shaking of Earth's crust.
What is an earthquake?
300
An instrument that records earthquake waves.
What is a seismograph?
300
The large basin formed at the top of a volcano.
What is a crater?
300
The stronger the earthquake the ____________ the waves are that are recorded on a seismograph.
What is bigger?
300
Different kinds of ____________ form different kinds of volcanic mountains like cinder cone volcanoes, composite volcanoes, and shield volcanoes.,
What are eruptions?
300
The thickest layer of Earth, made up of solid and partly melted rock.
What is the mantle?
400
The underground point where an earthquake first starts.
What is the focus?
400
Melted rock flowing from a volcano that reaches Earth's surface.
What is lava?
400
California has more than 20,000 earthquakes a year because there is a large ____________ running through the crust.
What is a fault?
400
Mount St. Helens was a volcano that erupted in which country.
What is United States?
400
The layer of Earth that includes land and the ocean foor.
What is the crust?
500
A break in Earth's crust along which rocks move.
What is a fault?
500
A mountain that forms when red-hot melted rock flows through a vent or crack onto Earth's surface.
What is a volcano?
500
Earth's plates move three different directions.
a. ________ b. ________ C. ________
What is towards, away, and past each other?
500
Iron and nickel make up this layer of Earth.
What is the inner core?
500
Scientists have a theory that all the continents were once one large land mass. They believe they started moving apart. This theory is called_________.