CHAPTER 14 Earthquakes and Earth’s Interior
354
TABLE 14.2
Some Notable Earthquakes
Year
Location
Deaths (est.)
Magnitude
†
Comments
1556
Shensi, China
830,000
Possibly the greatest natural disaster.
1755
Lisbon, Portugal
70,000
Tsunami damage extensive.
*1811–1812
New Madrid, Missouri
Few
7.9
Three major earthquakes.
*1886
Charleston, South Carolina
60
Greatest historical earthquake in the eastern United States.
*1906
San Francisco, California
3,000
7.8
Fires caused extensive damage.
1908
Messina, Italy
120,000
1923
Tokyo, Japan
143,000
7.9
Fire caused extensive destruction.
1960
Southern Chile
5,700
9.5
The largest-magnitude earthquake ever recorded.
*1964
Alaska
131
9.2
Greatest North American earthquake.
1970
Peru
70,000
7.9
Great rockslide.
*1971
San Fernando, California
65
6.5
Damage exceeded $1 billion.
1975
Liaoning Province, China
1,328
7.5
First major earthquake to be predicted.
1976
Tangshan, China
255,000
7.5
Not predicted.
1985
Mexico City
9,500
8.1
Major damage occurred 400 km from epicenter.
1988
Armenia
25,000
6.9
Poor construction practices.
*1989
San Francisco Bay area
62
7.1
Damages exceeded $6 billion.
1990
Iran
50,000
7.4
Landslides and poor construction practices caused great damage.
1993
Latur, India
10,000
6.4
Located in stable continental interior.
*1994
Northridge, California
60
6.7
Damages in excess of $15 billion.
1995
Kobe, Japan
5,472
6.9
Damages estimated to exceed $100 billion.
1999
Izmit, Turkey
17,127
7.4
Nearly 44,000 injured and more than 250,000 displaced.
1999
Chi-Chi, Taiwan
2,300
7.6
Severe destruction; 8,700 injuries.
2001
Bhuj, India
25,000 +
7.9
Millions homeless.
2003
Bam, Iran
41,000 +
6.6
Ancient city with poor construction.
2004
Indian Ocean (Sumatra)
230,000
9.1
Devastating tsunami damage.
2005
Pakistan/Kashmir
86,000
7.6
Many landslides; 4 million homeless.
2008
Sichuan, China
70,000
7.9
Millions homeless, some towns will not be rebuilt.
2010
Port-au-Prince, Haiti
230,000
7.0
More than 300,000 injured and a million homeless.
2010
Maule, Chile
486
8.8
One of the ten largest earthquakes by magnitude.
Source: U.S. Geological Survey
*U.S. earthquakes.
†
Widely differing magnitudes have been estimated for some of these earthquakes. When available, moment magnitudes are used.
spill. The Trans-Alaskan pipeline carries
nearly 20 percent of the domestic oil
supply of the United States—roughly
600,000 barrels per day—with a degree of
scientific reassurance that it will withstand
future displacement.
Long-range forecasts are based on
evidence that many large faults break
repeatedly, producing similar quakes at
roughly similar intervals. In other words,
as soon as a section of a fault ruptures, the
continuing motions of Earth’ s plates begin
to build strain in the rocks again until they
fail once more. As a result seismologists
study historical records of earthquakes to
see if there are any discernible patterns so
that the probability of recurrence may be
established.
With this concept in mind, seismologists plot the distribution of rupture zones
associated with great earthquakes around
the globe. The maps reveal that individual
rupture zones tend to occur adjacent to
one another without appreciable overlap,
thereby tracing out a plate boundary.
Because plates are moving at known velocities, the rate at which strain builds can also
be estimated.
Researchers’ study of historical records
led to the discovery that some seismic
zones had not produced a large earthquake
in more than a century, and in some locations, for several centuries. These quiet
zones, called seismic gaps, are believed to
be inactive zones that are storing strain
for future major quakes.
An area of recent interest to seismologists is the northern edge of the Indian
plate, which is colliding with Asia
(FIGURE 14.27). Although this area had
historically been seismically quiet, four
major earthquakes have struck the plate
354
TABLE 14.2
Some Notable Earthquakes
Year
Location
Deaths (est.)
Magnitude
†
Comments
1556
Shensi, China
830,000
Possibly the greatest natural disaster.
1755
Lisbon, Portugal
70,000
Tsunami damage extensive.
*1811–1812
New Madrid, Missouri
Few
7.9
Three major earthquakes.
*1886
Charleston, South Carolina
60
Greatest historical earthquake in the eastern United States.
*1906
San Francisco, California
3,000
7.8
Fires caused extensive damage.
1908
Messina, Italy
120,000
1923
Tokyo, Japan
143,000
7.9
Fire caused extensive destruction.
1960
Southern Chile
5,700
9.5
The largest-magnitude earthquake ever recorded.
*1964
Alaska
131
9.2
Greatest North American earthquake.
1970
Peru
70,000
7.9
Great rockslide.
*1971
San Fernando, California
65
6.5
Damage exceeded $1 billion.
1975
Liaoning Province, China
1,328
7.5
First major earthquake to be predicted.
1976
Tangshan, China
255,000
7.5
Not predicted.
1985
Mexico City
9,500
8.1
Major damage occurred 400 km from epicenter.
1988
Armenia
25,000
6.9
Poor construction practices.
*1989
San Francisco Bay area
62
7.1
Damages exceeded $6 billion.
1990
Iran
50,000
7.4
Landslides and poor construction practices caused great damage.
1993
Latur, India
10,000
6.4
Located in stable continental interior.
*1994
Northridge, California
60
6.7
Damages in excess of $15 billion.
1995
Kobe, Japan
5,472
6.9
Damages estimated to exceed $100 billion.
1999
Izmit, Turkey
17,127
7.4
Nearly 44,000 injured and more than 250,000 displaced.
1999
Chi-Chi, Taiwan
2,300
7.6
Severe destruction; 8,700 injuries.
2001
Bhuj, India
25,000 +
7.9
Millions homeless.
2003
Bam, Iran
41,000 +
6.6
Ancient city with poor construction.
2004
Indian Ocean (Sumatra)
230,000
9.1
Devastating tsunami damage.
2005
Pakistan/Kashmir
86,000
7.6
Many landslides; 4 million homeless.
2008
Sichuan, China
70,000
7.9
Millions homeless, some towns will not be rebuilt.
2010
Port-au-Prince, Haiti
230,000
7.0
More than 300,000 injured and a million homeless.
2010
Maule, Chile
486
8.8
One of the ten largest earthquakes by magnitude.
Source: U.S. Geological Survey
*U.S. earthquakes.
†
Widely differing magnitudes have been estimated for some of these earthquakes. When available, moment magnitudes are used.
spill. The Trans-Alaskan pipeline carries
nearly 20 percent of the domestic oil
supply of the United States—roughly
600,000 barrels per day—with a degree of
scientific reassurance that it will withstand
future displacement.
Long-range forecasts are based on
evidence that many large faults break
repeatedly, producing similar quakes at
roughly similar intervals. In other words,
as soon as a section of a fault ruptures, the
continuing motions of Earth’ s plates begin
to build strain in the rocks again until they
fail once more. As a result seismologists
study historical records of earthquakes to
see if there are any discernible patterns so
that the probability of recurrence may be
established.
With this concept in mind, seismologists plot the distribution of rupture zones
associated with great earthquakes around
the globe. The maps reveal that individual
rupture zones tend to occur adjacent to
one another without appreciable overlap,
thereby tracing out a plate boundary.
Because plates are moving at known velocities, the rate at which strain builds can also
be estimated.
Researchers’ study of historical records
led to the discovery that some seismic
zones had not produced a large earthquake
in more than a century, and in some locations, for several centuries. These quiet
zones, called seismic gaps, are believed to
be inactive zones that are storing strain
for future major quakes.
An area of recent interest to seismologists is the northern edge of the Indian
plate, which is colliding with Asia
(FIGURE 14.27). Although this area had
historically been seismically quiet, four
major earthquakes have struck the plate