The Richter Scale
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
4.4 - 4.8
Small unstable objects are moved. Dishes and glasses may
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
7.4 - 8.1
Few or no masonry structures remain standing. Bridges
destroyed. Underground pipelines completely destroyed.
Greater than 8.1 ---------------Damage nearly total!!
Deadliest Earthquakes on Record
January 23, 1556
China, Shansi 830,000
Deaths from earthquake and
July 27, 1976
Estimated death toll as high as
August 9, 1138
Syria, Aleppo 230,000
May 22, 1927
China, Gansu 200,000
Major fractures, landslides.
March 23, 893+
September 1, 1923
Great Tokyo fire.
..More Deadly Quakes
October 5, 1948
December 28, 1908
Deaths from earthquake and tsunami.
November 18, 1727
November 1, 1755
Portugal, Lisbon 70,000
December 25, 1932
May 31, 1970
$530,000,000 damage, great rock slide,
January 11, 1693
May 30, 1935
Quetta almost completely destroyed.
February 4, 1783
June 20, 1990
Deadliest US Earthquakes
Prince William Sound,
March 27, 19641.
Andreanof Islands, Alaska March 9, 1957
Rat Islands, Alaska
East of Shumagin Islands, Nov. 10, 1938
Lituya Bay, Alaska
July 10, 1958
Yakutat Bay, Alaska
Sept. 10, 1899
Near Cape Yakataga,
Sept. 4, 1899
Andreanof Islands, Alaska May 7, 1986
New Madrid, Missouri
Feb. 7, 1812
Fort Tejon, California
Jan. 9, 1857
Feb. 4, 1965
Famous U. S. Earthquakes
San Francisco Earthquake - 1906
*Time: 5:10 am
*8.2 on the
At 5:12 a.m. on April 18, 1906, a foreshock hit San Francisco. However, it offered just a quick
warning, for massive devastation was soon to follow. Approximately 20 to 25 seconds after
the foreshock, the large quake hit. With the epicenter near San Francisco, the entire city was
rocked. Chimneys fell, walls caved in, and gas lines broke. Asphalt that covered the streets
buckled and piled up. Many people didn't have time to even get out of bed before they
were killed by falling debris.
*3,000 killed by
quake and fire
*warm-up for the third game of the World Series
between the Oakland Athletics and the San Francisco
Because of the World Series game being held that evening, many people left work early
or gathered at restaurants to watch the game. This made the rush hour traffic lighter
than normal; otherwise, the death toll could have been much higher.
At Candlestick Park, only half of the fans had arrived when the earthquake hit. This
helped reduce the load and strain on the stadium structure. A seismic strengthening
project had recently been completed on the upper deck of the stadium. The stadium
was not damaged and the fans rode the wave and wanted the game to begin. It didn’t
happen; the game was postponed for 10 days.
New Madrid, Missouri Earthquakes 1811-1812
In December of 1811, a the
largest earthquake ever recorded
in American History started. This
earthquake, is called the New
Madrid Earthquake, because of its
location on the New Madrid Fault,
near New Madrid, Missouri.
December 16, 1811 – 8.1
January 23, 1822 – 7.8
February 7, 1812 – 8.8
Large areas sank into the earth, new
lakes were formed, waterfalls emerged,
and the Mississippi River changed its
course due to the earthquakes.
Survivors reported that the earthquakes caused cracks to open in the
earth's surface, the ground to roll in visible waves, and large areas of
land to sink or rise. The crew of the New Orleans (the first steamboat on
the Mississippi, which was on her maiden voyage) reported mooring to
an island only to awake in the morning and find that the island had
disappeared below the waters of the Mississippi River.