Activity
77: Our Fractured Earth: A Look at Fault Lines
How Strong Was It?
As amazing as it sounds, the Global
Positioning System satellites used by the
NASA are able to measure the movement of
Earth’s plates as the movements occur.
This is known as real-time measurement.
Seismologists use a special scale, called the Richter scale, to measure the
magnitude of earthquakes caused by movements of Earth’s tectonic plates.
1. What
device is used to measure the magnitude of an earthquake?
Seismograph
2.
What exactly does a
seismograph measure?
It measures and record the size and force of seismic
waves.
3.
True or False: A
seismograph can only detect earthquakes that occur
within a couple hundred miles.
False
4.
True or False: A Richter
scale specifies the magnitude of an earthquake by using a number, such as 6.2.
True
5.
What was the magnitude
of the Good Friday earthquake that occurred in
It had a magnitude of 9.2, and was the most powerful
recorded earthquake
in U.S.
and North
American history, and the third most powerful ever measured by seismograph.
6.
What is the approximate
magnitude required for an earthquake to be felt by people who are close by?
3.0-3.9
TechCONNECT © by the McGraw-Hill
Companies, Inc.