45 Interesting Facts About Earthquakes

1. The main reason behind earthquakes is the movement of plate tectonics in the earth’s crust. Naturally, earthquakes can also occur with volcanic eruptions.
2. Every year, around 500,000 earthquakes occur on earth. But most of these have very low intensity, and only 100,000 are noticeable.
3. Severe earthquakes cause material damage and loss of life on a large scale. These destructions are not always directly caused by earthquakes but instead by natural disasters triggered by these quakes. Tsunamis, volcanic eruptions, flooding, liquefaction, avalanches, and landslides are deadly natural disasters caused by earthquakes. (Source)
4. In the East African Rift System (EARS), the tectonic plates continuously try to create new plates by splitting the old ones. It is a rare example of an active continental rift zone. (Source) 
5. Earthquakes produce massive energy. An earthquake of magnitude 9 is equivalent to 99 million tons of TNT. It is the energy produced by 25,000 nuclear bombs and can destroy the whole earth. (Source)
6. The longest duration of an earthquake was recorded in 2004. Most earthquakes last for less than a minute. But the Sumatran-Andaman earthquake lasted almost 10 minutes and released energy equal to a 100-gigaton bomb. (Source)
7. Earthquakes sometimes produce mysterious lights such as bluish flames, floating ball lightning, and flashes of bright light. These are known as Earthquake Lights (EQL) and are the result of the electrical properties of certain rocks. These lights are seen before or during earthquakes and were previously thought to be caused by planes, birds, or UFOs. (Source)
8. Earthquakes have killed more than 140,000 people in just the last 12 years of the 20th Century: between 1988 and 2000. (Source)
9. More than 80% of all earthquakes occur in an area in the Pacific Ocean known as the Ring of Fire. This area (around 40,000 km) borders several countries in the Americas, Asia and Oceania.

   

   Most earthquake occur in Pacific Ring of Fire
   
   

10. The Alpide belt, located in the southern part of Eurasia, has the 2^nd highest rate of seismic activity. Around 15% of all earthquakes occur in this region. The Himalayas and the Alps are the chief mountain ranges of the alpide belt. (Source)
11. Very few earthquakes occur in Antarctica compared to other parts of the world. The reason is because the ice continent is away from major tectonic plates. (Source)
12. Weather and climate do not affect earthquakes. There is no specific weather for earthquakes, and they are distributed equally in all weather conditions. (Source)
13. The first earthquake detector was invented in 132 AD in China. The inventor of this initial seismoscope was a Chinese mathematician and engineer. (Source)
14. In 1935, Charles F. Richter developed the scale for the measurement of earthquakes. The scale is named after him, the Richter scale.
15. Every year, around 18 earthquakes between magnitude 7 and 7.9 and one earthquake with a magnitude of 8 or above are recorded.
16. The point inside the crust where an earthquake starts is known as the hypocenter. An epicenter is at the earth's surface directly above the hypocenter. (Source)
17. The strongest earthquake ever recorded was on 22^nd May 1960 in Chile. It had a magnitude of 9.5 and caused destruction even in Japan. (Source)
18. The deadliest earthquake in history took the lives of around 830,000 people in China in 1556. The country was also the victim of the world’s second-deadliest quake in 1976, which killed between 250,000 and 700,000 people.
19. An earthquake with a magnitude of 10 or above is highly unlikely. The fault required for a magnitude 12 earthquake is larger than the size of the earth, making it impossible to happen.
20. There are several misconceptions about earthquakes. In contrast to popular belief, an earthquake can not cause the opening up of the ground.
21. An 8.8 magnitude earthquake in Chile in 2010 shifted the earth’s axis and shortened the day length by 1.26 millionth of a second. A previous 9-magnitude earthquake in Sumatra shortened the day by 6.8 millionth of a second. (Source)
22. The world’s tallest tsunami ever recorded was caused by an earthquake on 9^th July 1958 in Lituya Bay, Alaska. This tsunami reached a height of 1720 feet. (Source)
23. Three types of faults can bring earthquakes. These are normal faults, thrust faults, and strike-slip faults. (Source)
24. The maximum depth of earthquakes is around 800 km as they occur in the crust or upper mantle. The impact of earthquakes on the surface reduces with increase in their depth. (Source)
25. The earliest earthquake with descriptive information occurred in 1177 B.C. in China. Europeans initially mentioned earthquakes in 580 B.C. (Source)
26. Earthquakes usually result from natural causes, but few human activities can also trigger quakes of large magnitude. Major human activities that can cause powerful and deadly earthquakes are mining, dam building, and nuclear explosions. (Source) 
    
27. Earthquakes can also occur in the middle of tectonic plates instead of the usual sites of their boundaries. These earthquakes are due to the motion of the earth’s mantle and can reach up to magnitude 7.0. (Source)

    

    Earthquakes can occur at boundaries and middle of plate tectonics

    
    
28. There are large numbers of tectonic plates present in the earth’s crust. They are divided into major, minor and micro tectonic plates. There are seven major plates of significant size. The largest one is the Pacific Plate, which covers an area of more than 103 million km². (Source)
29. The earthquake-proof buildings in Japan are made with carbon fiber in place of steel and concrete. This material increases the resistance of buildings against quakes due to its toughness and flexibility. (Source)
30. The history of quake-resistant buildings in Japan is old. Japan’s tallest wooden structure was constructed according to quake-resistant architecture. (Source)
31. Japan, Indonesia, Peru, China, Turkey, and Iran are among the most earthquake-prone countries in the world. It is due to their location near the Ring of Fire or major fault lines. 
32. Machu Picchu and other Incan buildings have quake-resistant features. These buildings can withstand even severe earthquakes. (Source)
33. An earthquake produces three types of seismic waves. P-waves are the first waves to be recorded by a seismograph. S-waves are slower than P-waves, but their larger amplitude makes them more destructive. Surface waves have the largest amplitude and are thus the most disastrous.
34. Standing water (ponds, lakes, etc.) gives a nasty smell and becomes warmer before the earthquake. It happens due to an accumulation of underground gases after plate shifting.
35. Aftershocks of large earthquakes can last for years. However, their frequency reduces with time. Swarms are small earthquakes that can continue for months. (Source)
36. Despite extreme efforts, scientists have not found a way to correctly predict the time and magnitude of an earthquake.
37. The depth of an earthquake also plays a vital role in causing damage. Shallow quakes are more destructive compared to those originating deep under the ground. However, deep-focus quakes are felt on a wide area than shallow quakes. (Source)
38. An earthquake of 7.8-magnitude killed 9,000 people in Nepal in 2015. Satellite images show that this earthquake has also shrunk Mt. Everest. (Source)
39. According to estimates, at least five types of animals can predict earthquakes. These include ants, toads, snakes, flamingos, and oarfish. (Source)
40. Some humans are also sensitive to earthquakes. They feel symptoms such as headache, nausea, blurry eyes, noise in the ears, etc. before an earthquake.
41. An earthquake in the Pacific Ocean with a magnitude of 7.9 caused massive landslides in Peru in 1970. It resulted in the demise of around 70,000 people. (Source)
42. The worst landslide on earth happened after an earthquake in 1920 in China. The magnitude 8 Haiyuan earthquake was one of the largest and deadliest earthquakes of the 20^th Century that resulted in the demise of more than 234,000 people. The top reason for these deaths was the collapse of houses, while around 32,000 died due to landslides. (Source) 
43. The earthquake and tsunami of 2004 brought several changes to the rotation and shape of the earth. It decreased the length of a day by 2.68 microseconds and slightly reduced the earth’s oblateness (a feature of bulging at the equator and flattening on the top). (Source)  
44. Tides on earth caused by the sun and moon can also trigger small tremors. It can indirectly result in setting off earthquakes. (Source)
45. There is evidence of quakes on the moon and Mars. There is also a possibility of quakes on Venus and the moons of Jupiter and Saturn.  Quakes on moons and other planets are also known as earthquakes. (Source)