Time Scale
Plate Tectonics
Earthquakes
Tsunamis
Volcanism
100

specifies divisions of times

What is the time scale?

100
theory of geophysical processes that explains the movement of lithospheric plates and the processes that occur at their boundaries
What is plate tectonics?
100
caused by fracturing and displacement of rock
What is an earthquake?
100
what tsunamis are usually called
What is a tidal wave?
100
a vent or fissure in the earth's surface thorugh which magma, liquid lava, and gases are released into the environment?
What is a volcano
200

how old the earth is

What is 4.5 billion years?

200
when oceanic plates move apart from one another
What is divergent plates?
200
where the earthquake starts
What is a focus?
200
killed how many people between 1900 and 2007
What is 278,000 people
200
molten rock below earth's surface
What is magma
300

people who study the earth

What are geologists?

300
when an oceanic plate collides with a continental plate
What is convergent plates?
300
severity of an earthquake
What is magnitude?
300
series of large waves generated when part of the oceaan floor rises or drops suddenly
What is a tsunami?
300
magma that reaches the earth's surface
What is lava?
400

a scale based on radioactivity in rocks

What is the radiometric time scale?

400
when the continental plate rides over the denser oceanic plate and pushes it down
What is subduction?
400
instrument used to record earthquakes
What is a seismograph?
400
helps protect land against tsunamis
What is a mangrove forest?
400
central vent or long crack
What is a fissure?
500

studying the origins of rocks

What is petrology?

500
where plates slide and grind past one another along a fault in the lithosphere
What is a transform fault?
500
the official scale that scientists use for earthquakes
What is the Richter Scale?
500
what tsunami detectors measure on the ocean floor before the tsunami
What is pressure?
500
worst volcano disaster in history
What is Mount St. Helens?
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