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Famous Earthquakes
These are some of history's most notable — and devastating — earthquakes.

San Francisco, California: April 18, 1906 (Magnitude: About 8)
In response to growing forces on the Pacific and North American tectonic plates, a horizontal slip amounting to several yards occurred suddenly at 5:12 A.M. local time on the San Andreas Fault for a distance of more than 248 miles (400 kilometers). It went through the city and far outside it, down to a depth of about 6 miles (10 kilometers). This was one of the rare earthquakes in which the fault slip was easily visible at the Earth's surface. Brick buildings in the city collapsed. Even though most of the wooden frame buildings survived the strong shaking, they did not survive the fires that burned for days over several hundred city blocks. The fires caused most of the death toll — about 500 people.

Tokyo, Japan: September 1, 1923 (Magnitude: About 8.25)
In the years following the San Francisco disaster, a young Japanese seismologist tried to persuade his older colleagues that Tokyo should be prepared for another earthquake like the one in 1703 that had been very destructive. His warnings were not heeded, and in 1923 a great earthquake caused extensive damage in Yokohama and Tokyo by direct shaking and by fires. About 140,000 people died.

Chile: May 22, 1960 (Magnitude: About 9)
Forces pushing the Pacific and the South American tectonic plates together caused a fault slip of about 66 feet on a fault surface that was so large — more than 620 miles long and about 124 miles wide — that we associate this earthquake with an entire country. This was one of the two largest earthquakes, in terms of seismic moment, in a century. At the time, there were few instruments operating that could measure very long surface waves. But from the available records, it was apparent for days after this earthquake that the shock made the whole Earth ring like a gigantic bell.

Anchorage, Alaska: March 27, 1964 (Magnitude: About 8.5)
Growing forces pushing the Pacific and the North American tectonic plates toward each other caused the Pacific plate to slip about 42 feet at an angle beneath Alaska and beneath the seafloor just south of the port of Anchorage, which was destroyed. Seismometers that detect surface waves around the world were knocked off scale for hours. When recording resumed, they were measuring surface waves that continued to go around the Earth for several days, again as if the whole Earth were ringing and at exactly the same frequencies as the great Chilean earthquake nearly 4 years earlier. Large amounts of water were almost immediately moved up or down several yards because the main fault surface that broke was beneath the ocean floor. This seafloor motion caused a tsunami, or water wave, that traveled all over the Pacific Ocean, causing further damage, even killing people on a beach in California.

Tangshan, China: July 27, 1976 (Magnitude: About 7.5)
A devastating earthquake occurred in eastern China, about 100 miles from Beijing in a coal-mining area where thousands of people worked underground day and night. In the densely populated town of Tangshan, buildings were constructed with heavy masonry but with no special precautions to withstand earthquake shaking. About 240,000 people died. In this part of the world, the boundary between tectonic plates is not clearly defined. Rather, it appears as if a region millions of square miles in extent is deforming, or changing shape, not by a steady process but by earthquakes.

Sumatra, Indonesia, Dec. 26, 2004. (Magnitude: About 9.0)
A 9.0 magnitude earthquake � the largest earthquake in 40 years � caused a powerful tsunami in the Indian Ocean that devastated 12 Asian countries. The earthquake's epicenter was off the west coast of the Indonesian Island of Sumatra. A week later the death toll was estimated at 150,000 � a month later some estimate double that number. Hardest hit were Indonesia (particularly the province of Aceh), Sri Lanka, India, Thailand, and the Maldives. Millions of people lost their homes. Since entire families and towns were destroyed and bodies were swept out to sea, it's possible we will never know the total number lives lost.