4th Grade Unit C Ch. 1 Earthquakes and Volcanoes
Some volcanoes form new ___________ as plates move apart and magma rises to the surface of the crust.
Earth's ________ is its hottest layer.
Scientist can __________ earthquakes by using seismographs, the Mercalli scale, and the Richter scale.
California has more than 20,000 earthquakes each year, because there is a large ___________ running through the state.
All eruptions _______ form the same kinds of volcanic mountains because the shape of a volcano depends on what type of materials it erupts. There are different eruptions for different volcanoes.
Earth's plates move very slowly across Earth's surface on a thin layer of partly melted _________.
The inner core, the outer core, the mantle, and the crust are the _______ of the Earth.
The 1964 Alaska earthquake released more energy than the 1989 California earthquake as measured by the ____________ (size of waves) and the intensity using a Richter scale.
If Earth's plates stopped moving, then the Earth's core would cool and no new mountains would form. Then rain would erode the Earth's surface until it was flat and covered with water.
Ring of Fire
The _____________ is an area with frequent earthquakes and volcanic eruptions that circles the Pacific Ocean.
_________ is the point underground where the movement of an earthquake first took place.
________ is the melted rock inside the Earth.
________ is the melted rock that reaches Earth's surface.
________ is the point on the surface of Earth that is right above the focus of an earthquake.
__________ is the rocky tube in a volcano through which magma rises toward the surface.
_________ is an instrument that records earthquake waves.
_________ is an underground pool below a volcano that holds magma.
________ is a mountain that forms when red-hot melted rock flows through a crack onto Earth's surface.
________ is a large basin formed at the top of a volcano when the top falls in on itself.
_______ is the Earth's outer layer and includes the rock of the ocean floor and large areas of land.
________ is the thickest layer of Earth and is found just below the crust.
_______ is a break in the Earth's crust along which rocks move.
_______ is a vibration, or shaking, of the Earth's crust.
_______ is a continent-sized slab of Earth's crust and upper mantle.
_______ is the dense center of the Earth and is a ball made mostly of two metals (iron and nickel).