Download scale to rate the total energy an earthquake releases

HONORS EARTH SCIENCE HOMEWORK
How Earthquakes are measured, pgs 130, 132-133
1. The __________ is the area beneath Earth’s surface where rock
that was under stress begins to _______ or _________.
2. This action triggers an ____________.
3. The point on the surface directly above the focus is called the
____________.
4. Most earthquakes start in the __________, within about 100
kilometers (about 62 miles) beneath Earth’s _________.
5. ___________ _________ carry energy from the earthquake’s
focus.
6. Geologists monitor earthquakes by measuring the _________
_________ that they produce.
7. A ______________ is an instrument that records and measures
an earthquake’s seismic waves.
8. The __________ __________ scale rates the amount of shaking
that results from an earthquake. The shaking is rated by
people’s _________, without the use of any instruments.
9. The Modified Mercali scale uses __________ ___________ to
rate the damage and shaking at any given location (132, Figure
3, “Interactive Art”, bottom right of page)
10. An earthquake’s ___________ is a single number that
geologists assign to an earthquake based on the earthquake’s
________.
11. There are many magnitude scales. These scales are based on
the earliest magnitude scale, called the _________ scale.
12. Magnitude scales like the Richter scale rate the magnitude
of small earthquakes based on the size of the earthquake’s
________ as recorded by seismographs.
13. The magnitudes take into account that seismic waves get
__________ (meaning weaker) the farther the seismograph is
from an earthquake.
14. Geologists use the ___________ ____________ scale to
rate the total energy an earthquake releases. News reports
may mention the Richter scale, the number quoted is almost
always an earthquake’s _________ __________.
15. To assign a magnitude to an earthquake, geologists use data
from __________ and other _________.
16. An earthquakes moment magnitude tells geologists how
much ________ was released by an earthquake.
17. Each one-point increase in magnitude represents the release
of roughly _____ times more energy. For example, a magnitude
6 earthquake releases 32 times as much ________ as a
magnitude _______ earthquake.
18. An earthquakes effects ________ with magnitude.
Earthquakes with a magnitude below ____ are small and cause
little ________.
19. Those with a __________ above 6 can cause great damage.
The most powerful earthquakes, with a magnitude of ____ or
above, are rare.
20. In the 1900’s, only three earthquakes had a magnitude of
____ or above.