Here are some interesting facts about earthquakes.
- An earthquake is caused by a sudden release of energy in the earth’s crust. This leads to a seismic wave, or wave of energy, which travels under or across the earth’s surface.
- Every year there are over 1.3 million earthquakes all over the world. One occurs every 11 seconds, although most of them are not strong enough to be noticed or cause damage.
- The Richter Scale was devised in 1935 by a geologist Charles Richter. It measures the intensity of earthquakes by giving them a number between 1 and 10.
- One of the deadliest earthquakes ever was in Shaanxi, China, in 1556, killing over 800,000 people. One of the worst in the 21st century was in Haiti in 2010, when over 300,000 were killed.
- The San Francisco earthquake of April, 1906 is one of the most famous. Over 80 percent of the city was destroyed and fires burned for several days.
- An earthquake measuring 8.8 in Chile in 2010 was so strong that it moved the city of Concepcion several metres. It also changed the rotation of the earth slightly.
- One of the most powerful earthquakes measured 9.5 in Valdivia, Chile in 1960.
- The 2004 quake in the Indian Ocean led to huge waves which killed over 200,000 people in over a dozen countries.
- Extracting oil from the ground sometimes causes small earthquakes.
- Most quakes occur in the Pacific Ring of Fire, the area around the Pacific Ocean. However, they are now more likely in Africa, America and Australia too.
- It is impossible to accurately predict when and where an earthquake will happen. Some animals, however, are thought to be able to sense seismic activity hours or even days before it happens.
