6th Grade Science Unit 3 - Tectonics, Earthquakes, Volcanoes

The outermost layer of the Earth is the ______________.
Check the statements below that are true:
1. The Oceanic crust is thicker than the Continental crust.
2. The Oceanic crust is denser than the Continental crust
3. The Continental crust is thicker than the Oceanic crust.
4. The Continental crust is denser than the Ocenaic crust.
Which layer contains most of the Earth's mass?
1. crust
2. mantle
3. core
The Earth's core is made MOSTLY of:
1. oxygen
2. nickel
3. iron
4. silicon
5. luster
The soft layer of the mantle on which the tectonic plates move is the ___________________ .
Which part of the Earth's core is solid?
1. Outer Core
2. Inner Core
A block of lithosphere that consists of the crust and the rigid ,outermost part of the mantle is called a ________ ________.
Which tectonic plate includes both continental crust and oceanic crust?
1. North American plate
2. South American plate
3. Cocos plate
The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations is called ________ ___________ .
In the process of sea-spreading, new oceanic ________________ forms as magma rises towards the surface and solidifies.
The polarity of the Earth's magnetic field can never change over time.
1. True
2. False
At mid-ocean ridges:
1. tectonic plates are colliding
2. the crust is older
3. oceanic lithosphere is destroyed
4. sea-floor spreading occurs
When two tectonic plates slide past each other horizontally, the boundary between them is a ______________.
1. convergent boundary
2. divergent boundary
3. transform boundary
All tectonic plate movement requires some form of _____________ to be expended.
The process where the edge of the tectonic plate that contains oceanic lithosphere sinks and pulls the rest of the tectonic plate with it is called:
1. convection
2. slab pull
3. ridge push.
The type of stress that occurs when two tectonic plates collide is called ______________ .
The surface along which rocks break and slide past each other is called a ____________ .
The majority of tectonically active volcanic mountains on Earth have formed around the tectonically active rim of the _______ ocean.
1. Atlantic
2. Indian
3. Pacific
4. Artic
The highest mountains in the world are made up of:
1. volcanic mountains
2. folded mountains
3. falut-block mountains
Scientists knowledge of the Earth's interior has come primarily from:
1. using a global positioning system
2. studying the pattern of fossils on different continents
3. studying seismic waves generated by earthquakes
4. studying magnetic reversals in oceanic crust
Which type of deformation leads to earthquakes?
1. plastic
2. elastic
The study of earthquakes is called:
The direct cause of earthquakes is:
1. deformation
2. seismic waves
3. elastic rebound
The fastest wave of earthquake energy is the:
1. P wave
2. S wave
3. surface wave
The more destructive earthquake waves are _____________ waves.
When rock is _______________, energy builds up in it. Seismic waves occur as this energy is ___________.
1. plastically deformed, released
2. elastically deformed, increased
3. plastically deformed, increased
4. elastically deformed, released
The point on the Earth's surface directly above an earthquakes starting point is called the ______________.
A vent or fissure in the Earth's surface through which magma and gases pass is called a _________________.
A body of molten rock that feeds a volcano is called a ___________________.
1. vent
2. lava chamber
3. magma chamber
4. crater
An explosive eruption is more likely when the water content of the magma is
1. high
2. low
3. it doesn't matter
An explosive eruption is more likely when the silica content of the magma is
1. high
2. low
3. it doesn't matter
Explosive eruptions produce mostly _____________ .
1. lava
2. pyroclastic material
Pyroclastic flows can travel downhill at speeds of more than
1. 20 km/h
2. 2,000 km/h
3. 200 km/h
4. 2 km/h
The most common cause of magma formation is a ____________ in pressure.
1. decrease
2. increase
Magma is _________ than the surrounding rock so it slowly rises toward the surface.
1. more dense
2. less dense
The central vent at the top of many volcanoes is a funnel-shaped pit called a __________.
Volcanoes that are formed by the combination of explosive eruptions of pyroplastic material and quieter flows of lava are __________ volcanoes.
1. shield
2. cinder cone
3. composite
4. extinct
Pyroclastic material may consist of: (check all that apply)
1. hot ash
2. slow moving lava
3. gases
4. dust
5. molten iron
The direct cause of an explosive volcanic eruption is the build-up of _______________ .
Dormant volcanoes will never erupt again
1. True
2. False