Earthquakes And Richter Scale Magnitude Worksheet Template
ADVERTISEMENT
1
2Earthquakes and Richter Magnitude
NAME_______________________________________
Recent
major
earthquakes
have
devastated
Haiti,
Chile
and
Turkey.
The
following
is
a
simplified
explanation
of
the
Richter
scale.
It
will
help
us
make
some
comparisons
between
earthquakes
of
various
strengths.
More
recently,
Dr.
Hiroo
Kanamori
came
up
with
a
relationship
between
seismic
moment
and
seismic
wave
energy.
It
Energy
=
(Moment)/20,000
gives:
For
this
moment
is
in
units
of
dyne‐cm,
and
energy
is
in
units
of
ergs.
dyne‐cm
and
ergs
are
unit
equivalents,
but
have
different
physical
meaning.
Let's
take
a
look
at
the
seismic
wave
energy
yielded
by
our
two
examples,
in
comparison
to
that
of
a
number
of
earthquakes
and
other
phenomena.
For
this
we'll
use
a
larger
unit
of
energy,
the
seismic
energy
yield
of
quantities
of
the
explosive
TNT
(We
assume
one
ounce
of
TNT
exploded
below
ground
yields
640
million
ergs
of
seismic
wave
energy):
Richter
TNT for Seismic
Example
Magnitude
Energy Yield
(approximate)
-1.5
6 ounces
Breaking a rock on a lab table
1.0
30 pounds
Large Blast at a Construction Site
1.5
320 pounds
2.0
1 ton
Large Quarry or Mine Blast
2.5
4.6 tons
3.0
29 tons
3.5
73 tons
4.0
1,000 tons
Small Nuclear Weapon
4.5
5,100 tons
Average Tornado (total energy)
5.0
32,000 tons
5.5
80,000 tons
Little Skull Mtn., NV Quake, 1992
6.0
1 million tons
Double Spring Flat, NV Quake, 1994
6.5
5 million tons
Northridge, CA Quake, 1994
7.0
32 million tons
Hyogo-Ken Nanbu, Japan Quake, 1995; Largest
Thermonuclear
Weapon
7.5
160 million tons
Landers, CA Quake, 1992
8.0
1 billion tons
San Francisco, CA Quake, 1906
8.5
5 billion tons
Anchorage, AK Quake, 1964
9.0
32 billion tons
Chilean Quake, 1960
10.0
1 trillion tons
(San-Andreas type fault circling Earth)
12.0
160 trillion tons
(Fault Earth in half through center,
i
OR Earth's daily receipt of solar energy)
Questions:
1. According to the table what magnitude earthquake releases a similar amount of energy to small
nuclear weapon?
2. How many pounds of energy would we expect for a magnitude of zero energy yield?
3. According to the chart, how many times greater is a 5.0 magnitude quake than a 4.0 magnitude
quake?
ADVERTISEMENT
0 votes
Related Articles
Related forms
Related Categories
Parent category: Education