D. The Richter magnitude scale uses a logarithmic scale to measure the amount of seismic energy released by an earthquake. Using the mathematical formula created by Charles Richter and Beno Gutenberg, energy increases exponentially on the scale. Japan's quake was the fifth-largest in the world.

Q: Most of the deaths and damage in Japan were caused by tsunami waves from the Pacific Ocean, where the earthquake was centered. A 2004 tsunami that killed more than 230,000 people in 14 countries was caused by an earthquake in the . . .

A. Atlantic Ocean

B. Indian Ocean

C. Pacific Ocean

D. Caribbean Sea

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B. The 2004 earthquake was centered off the coast of Indonesia and the resulting tsunami killed people as far away as South Africa - 4,971 miles from the epicentre. The Indian Ocean tremor was the world's third largest recorded earthquake.

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Q: Japan, New Zealand and Indonesia all lie in an area where large numbers of earthquakes and volcanic eruptions occur. What is this zone called?

A. Pacific Ring of Fire

B. Great Pacific Fault

C. Tectonic Terror

D. Pacific Ridge

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A. About 90 percent of the world's earthquakes and 80 percent of the world's largest earthquakes occur along the Ring of Fire on the edges of the Pacific Ocean. It also is home to 75 percent of the world's active and dormant volcanoes.

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Q: The Japan tsunami severely damaged nuclear reactors, causing the worst nuclear power crisis since the 1986 disaster at the Chernobyl plant in . . .

A. Belarus

B. Russia

C. Ukraine

D. Pennsylvania

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C. Ukraine was part of the former Soviet Union when the accident happened. Explosions released a radioactive plume that spread over Europe and severely contaminated a wide area around the plant.

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