Earthquake
(Move your
mouse over the rocks to see the earthquake.)
Earth
has about 800 moderate earthquakes every year. Another 120 earthquakes occur each
year in the strong range. About 18 major earthquakes come, and one great earthquake will
take place each year. Since 1990 112,199 people have died in earthquakes throughout the
world. Sixty-eight of these deaths were in the United States. The United States has around
3000 earthquakes each year. Although the majority of these are below the moderate range,
approximately 10 earthquakes take place annually in the United States are in the
destructive range.
Earthquakes are measured using a scale called the Richter Scale. This scale ranks
earthquakes from 1 to 12. If the earthquake is below 2.0 you usually can't feel it.
Earthquakes that rank below the 4.0 usually do not cause damage. Earthquakes over 5.0 can
cause damage. If the earthquake is 7.0 or higher on the Richter Scale it is considered a
major earthquake. Below you will see a chart that explains the Richter Scale in more
detail.
| Less than 4.3 |
No damage |
| 4.4 - 4.8 |
Small unstable objects are moved. Dishes
are glasses may be broken. |
| 4.9 - 5.4 |
Damage slight. Windows, dishes, and
glasses may be broken. Furniture moved. Weak masonry cracked. |
| 5.5 - 6.1 |
Structural damage considerable |
| 6.6 - 6.9 |
Structural damage severe. Underground
pipes broken. Cracks in ground. |
| 7.0 - 7.3 |
Most masonry and frame structure
foundations destroyed. Some well built wooden structures and bridges destroyed. |
| 7.4 - 8.1 |
Few or no masonry structures remain
standing. Bridges destroyed. Underground pipelines completely destroyed. |
| Greater than 8.1 |
Damage nearly total. |
Although most of the largest earthquakes have occurred in other nations of our world the
United States has had its share of serious quakes. The 10 largest earthquakes as measured
by the Richter Scale in the United States are listed below:
| Where |
Date |
Size |
Deaths |
| Prince William Sound |
3/28/1964 |
9.2 |
125 |
| Andrean of Islands |
3/09/1957 |
8.8 |
|
| Rat Islands |
2/04/1965 |
8.7 |
|
| Shumagin Islands |
11/10/1938 |
8.3 |
|
| Lituya Bay, Alaska |
7/10/1958 |
8.3 |
5 |
| Yakutat Bay |
9/10/1899 |
8.2 |
|
| Cape Yakataga, Alaska |
9/04/1899 |
8.2 |
|
| Andrean of Islands, Alaska |
5/07/1986 |
8.0 |
|
| New Madrid |
1811-1812 |
|
40 |
| Fort Tejon |
1/09/1857 |
7.9 |
1 |
Some other large U. S. earthquakes are:
Northridge,
California
(20 miles from
Los Angeles) |
January 17, 1994
4:31 a.m. |
Magnitude: 6.7 |
Deaths: 57
Injuries: 9,000 |
Property Damage:
$15 billion |
| Loma Prieta
Earthquake (south of San Francisco) |
October 17, 1989
5:04 p.m.
Length of time:
15 seconds |
|
Deaths: 62
Injuries: 3,757 |
Property Damage:
More than $6 billion
|
| Coalinga, CA |
May 2, 1983 |
Magnitude: 6.4 |
Deaths: 0
Injuries: 47 |
Property damage:
$31 million |
| San Francisco, CA |
April 18, 1906
5:12 a.m. |
Magnitude: 8.25
Length of time:
40 seconds |
Deaths: 700 to 2,500 people |
|
Could
earthquake safety education help prevent accidents? Follow the links below so you will be
better prepared when faced with an earthquake. Then take the quiz to determine how much
you have learned.
Preparation and Prevention
When an Accident Occurs
Online Quiz on Earthquake Safety
|
