At least 233 people died, 1,560 injured and tens of thousands displaced, while hundreds of buildings were destroyed by a 7.8 quake April 17, 2016 in Ecuador. | Photo: AFP
1. About 80 percent of all earthquakes occur along the rim of the Pacific Ocean, called the Ring of Fire, where there are 452 volcanoes or 75 percent of the world's most active and dormant volcanoes. Natural events such as volcanic eruptions and meteor impacts can cause earthquakes, but the majority of are triggered by movement of the Earth's plates.
2. The Earth's surface consists of 20 constantly moving plates. The pressure increase from shifting plates can cause the crust to break, causing earthquakes.
3. There are about 1.3 million earthquakes a year. Most are 2.9 magnitude or lower.
4. There are about 10,000 earthquakes a year in California alone.
5. Earthquakes kill approximately 8,000 people each year and have caused an estimated 13 million deaths in the past 4,000 years.
6. Earthquakes are mostly caused by geological faults, but they can also be caused by landslides, nuclear testing, mine tests, and volcanic activity.a
7. Earthquakes can set off volcanoes, as was the case in the 1980 Mount St. Helens eruption and the Mount Etna eruption in 2002.
8. At least one 8 magnitude quake occurs every year.
9. An earthquake can release hundreds times more energy than the nuclear bomb that was dropped on Hiroshima in Japan in 1945.
10. Quakes on one side of Earth can rattle the other side. Scientists studying the massive 2004 earthquake that caused tsunamis across the Indian Ocean found that the quake had weakened at least a portion of California's San Andreas Fault. The Chilean quake of 1960 shook the entire Earth for many days.
11. The deadliest earthquake ever struck January 23, 1556 in Shansi, China. Some 830,000 are estimated to have died.
12. The worst earthquake ever apparently occurred in A.D. 1201 in the eastern Mediterranean. It killed over one million people.
13. The largest recorded earthquake in the world was a magnitude 9.5 in Chile on May 22, 1960. The largest in the U.S. was a magnitude 9.2 that struck Prince William Sound, Alaska on March 28, 1964.
14. The world’s worst landslide started by an earthquake occurred in 1920 in the Kansu province in China. The landslide killed about 200,000 people, while the highest tsunami happened in Japan in 1771 generating waves as high as 85 meters or just over 255 feet.
15. Scientists think that animals may sense weak tremors before a quake. Other scientists think that animals may sense electrical signals set off by the shifting of underground rocks.
A year ago in Nepal, a powerful quake killed 1,300 people. | Photo: Reuters
16. The San Andreas Fault is moving about 2 inches a year. At this rate, San Francisco and Los Angeles will be next to each other in 15 million years.
17. Japan’s massive 2011 earthquake shifted the earth’s mass toward the center, causing the planet to spin faster and shortening the day by 1.6 microseconds. The 2004 Sumatra quake shorted the day by 6.8 microseconds.
18. The sun and moon cause tremors. It's long been known that they create tides in the planet's crust, very minor versions of ocean tides. Now researchers say the tug of the sun and moon on the San Andreas Fault stimulates tremors deep underground.
19. A city in Chile moved 10 feet in the massive 8.8 magnitude earthquake Feb. 27, 2010. The rip in Earth's crust shifted the city of Concepcion that much to the west. The quake is also thought to have changed the planet's rotation slightly and shortened Earth's day.
The September 1985 earthquake in Mexico City killed over 25,000 people. | Photo: File