Richter Scale

1

• example 5

• Richter Scale

Because the intensities of earthquakes are so
large, the Richter scale was developed to provide
a scaled down measuring system that permits
earthquakes to be more easily measured and
compared. The Richter scale gives the magnitude R
of an earthquake using the formula where I is
the intensity of the earthquake and I0 is a
certain minimum intensity used for comparison.

• Chapter 5.2

?2009 PBLPathways
2
Because the intensities of earthquakes are so
large, the Richter scale was developed to provide
a scaled down measuring system that permits
earthquakes to be more easily measured and
compared. The Richter scale gives the magnitude R
of an earthquake using the formula where I is
the intensity of the earthquake and I0 is a
certain minimum intensity used for comparison.
3
The following table describes the typical effects
of earthquakes of various magnitudes near the
epicenter.
Description Richter Magnitudes Earthquake Effects
Micro Less than 2.0 Microearthquakes, not felt
Very minor 2.02.9 Generally not felt, but recorded
Minor 3.03.9 Often felt, but rarely causes damage
Light 4.04.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely
Moderate 5.05.9 Can cause damage to poorly constructed buildings over small regions
Strong 6.06.9 Can be destructive in areas up to about 100 miles across in populated areas
Major 7.07.9 Can cause serious damage over larger areas
Great 8.08.9 Can cause serious damage in areas several hundred miles across
Rarely, great 9.09.9 Devastating in areas several thousand miles across
Meteoric 10 Never recorded
4

1. If an earthquake has an intensity of 10,000 times
   I0 , what is the magnitude of the earthquake?
   Describe the effects of this earthquake.
2. Show that if the Richter scale reading of an
   earthquake is k, the intensity of the earthquake
   is .
3. An earthquake that measured 9.0 on the Richter
   scale occurred in the Indian Ocean in December
   2004, causing a devastating tsunami that killed
   thousands of people. Express the intensity of
   this earthquake in terms of I0.
4. If an earthquake measures 7.0 on the Richter
   scale, give the intensity of this earthquake in
   terms of I0. How much more is the intensity of
   the earthquake in part (c) than the one with
   Richter scale measurement of 7.0?

5

1. If an earthquake has an intensity of 10,000 times
   I0 , what is the magnitude of the earthquake?
   Describe the effects of this earthquake.

Description Richter Magnitudes Earthquake Effects
Light 4.04.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely
6

1. If an earthquake has an intensity of 10,000 times
   I0 , what is the magnitude of the earthquake?
   Describe the effects of this earthquake.

Description Richter Magnitudes Earthquake Effects
Light 4.04.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely
7

1. If an earthquake has an intensity of 10,000 times
   I0 , what is the magnitude of the earthquake?
   Describe the effects of this earthquake.

Description Richter Magnitudes Earthquake Effects
Light 4.04.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely
8

1. If an earthquake has an intensity of 10,000 times
   I0 , what is the magnitude of the earthquake?
   Describe the effects of this earthquake.

Description Richter Magnitudes Earthquake Effects
Light 4.04.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely
9

1. If an earthquake has an intensity of 10,000 times
   I0 , what is the magnitude of the earthquake?
   Describe the effects of this earthquake.

Description Richter Magnitudes Earthquake Effects
Light 4.04.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely
10

1. If an earthquake has an intensity of 10,000 times
   I0 , what is the magnitude of the earthquake?
   Describe the effects of this earthquake.

Description Richter Magnitudes Earthquake Effects
Light 4.04.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely
11

1. If an earthquake has an intensity of 10,000 times
   I0 , what is the magnitude of the earthquake?
   Describe the effects of this earthquake.

Description Richter Magnitudes Earthquake Effects
Light 4.04.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely
12

1. If an earthquake has an intensity of 10,000 times
   I0 , what is the magnitude of the earthquake?
   Describe the effects of this earthquake.

Description Richter Magnitudes Earthquake Effects
Light 4.04.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely
13

1. If an earthquake has an intensity of 10,000 times
   I0 , what is the magnitude of the earthquake?
   Describe the effects of this earthquake.

Description Richter Magnitudes Earthquake Effects
Light 4.04.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely
14

1. Show that if the Richter scale reading of an
   earthquake is k, the intensity of the earthquake
   is .

15

1. Show that if the Richter scale reading of an
   earthquake is k, the intensity of the earthquake
   is .

16

1. Show that if the Richter scale reading of an
   earthquake is k, the intensity of the earthquake
   is .

17

1. Show that if the Richter scale reading of an
   earthquake is k, the intensity of the earthquake
   is .

18

1. Show that if the Richter scale reading of an
   earthquake is k, the intensity of the earthquake
   is .

19

1. Show that if the Richter scale reading of an
   earthquake is k, the intensity of the earthquake
   is .

20

1. Show that if the Richter scale reading of an
   earthquake is k, the intensity of the earthquake
   is .

21

1. Show that if the Richter scale reading of an
   earthquake is k, the intensity of the earthquake
   is .

22

1. An earthquake that measured 9.0 on the Richter
   scale occurred in the Indian Ocean in December
   2004, causing a devastating tsunami that killed
   thousands of people. Express the intensity of
   this earthquake in terms of I0.

1. If an earthquake measures 7.0 on the Richter
   scale, give the intensity of this earthquake in
   terms of I0. How much more is the intensity of
   the earthquake in part (c) than the one with
   Richter scale measurement of 7.0?

23

1. An earthquake that measured 9.0 on the Richter
   scale occurred in the Indian Ocean in December
   2004, causing a devastating tsunami that killed
   thousands of people. Express the intensity of
   this earthquake in terms of I0.

1. If an earthquake measures 7.0 on the Richter
   scale, give the intensity of this earthquake in
   terms of I0. How much more is the intensity of
   the earthquake in part (c) than the one with
   Richter scale measurement of 7.0?

24

1. An earthquake that measured 9.0 on the Richter
   scale occurred in the Indian Ocean in December
   2004, causing a devastating tsunami that killed
   thousands of people. Express the intensity of
   this earthquake in terms of I0.

1. If an earthquake measures 7.0 on the Richter
   scale, give the intensity of this earthquake in
   terms of I0. How much more is the intensity of
   the earthquake in part (c) than the one with
   Richter scale measurement of 7.0?

25

1. An earthquake that measured 9.0 on the Richter
   scale occurred in the Indian Ocean in December
   2004, causing a devastating tsunami that killed
   thousands of people. Express the intensity of
   this earthquake in terms of I0.

1. If an earthquake measures 7.0 on the Richter
   scale, give the intensity of this earthquake in
   terms of I0. How much more is the intensity of
   the earthquake in part (c) than the one with
   Richter scale measurement of 7.0?

26

1. An earthquake that measured 9.0 on the Richter
   scale occurred in the Indian Ocean in December
   2004, causing a devastating tsunami that killed
   thousands of people. Express the intensity of
   this earthquake in terms of I0.

1. If an earthquake measures 7.0 on the Richter
   scale, give the intensity of this earthquake in
   terms of I0. How much more is the intensity of
   the earthquake in part (c) than the one with
   Richter scale measurement of 7.0?

27

1. An earthquake that measured 9.0 on the Richter
   scale occurred in the Indian Ocean in December
   2004, causing a devastating tsunami that killed
   thousands of people. Express the intensity of
   this earthquake in terms of I0.

1. If an earthquake measures 7.0 on the Richter
   scale, give the intensity of this earthquake in
   terms of I0. How much more is the intensity of
   the earthquake in part (c) than the one with
   Richter scale measurement of 7.0?

28

1. An earthquake that measured 9.0 on the Richter
   scale occurred in the Indian Ocean in December
   2004, causing a devastating tsunami that killed
   thousands of people. Express the intensity of
   this earthquake in terms of I0.

1. If an earthquake measures 7.0 on the Richter
   scale, give the intensity of this earthquake in
   terms of I0. How much more is the intensity of
   the earthquake in part (c) than the one with
   Richter scale measurement of 7.0?

29

1. An earthquake that measured 9.0 on the Richter
   scale occurred in the Indian Ocean in December
   2004, causing a devastating tsunami that killed
   thousands of people. Express the intensity of
   this earthquake in terms of I0.

1. If an earthquake measures 7.0 on the Richter
   scale, give the intensity of this earthquake in
   terms of I0. How much more is the intensity of
   the earthquake in part (c) than the one with
   Richter scale measurement of 7.0?