There are two kinds of rulers used to measure earthquake intensity.

One is called earthquake magnitude;

One is called seismic intensity.

For example, the magnitude of an earthquake is like a fluorescent lamp with different wattage. The higher the wattage, the greater the energy and the higher the amplitude. The intensity is like the light level in the room. The same fluorescent lamp, the distance from the fluorescent lamp is different, and the exposure of each place is different, so the intensity of each place is different.

Earthquake magnitude is the standard to measure the magnitude of an earthquake. Each earthquake has only one magnitude. It is divided according to the energy released during the earthquake. Magnitude can be calculated from the records of seismic instruments. The higher the magnitude, the more energy is released. The magnitude standard used in China is an international standard, which is called "Richter scale". Earthquake grading standards vary from country to country and from region to region.

Generally speaking, earthquakes with magnitude less than 1 are called ultrashort earthquakes.

◢ Earthquakes with magnitude greater than or equal to 1 and less than 3 are called weak earthquakes or microseisms.

Earthquakes greater than or equal to magnitude 3 and less than magnitude 4.5 are called inductive earthquakes.

If it is greater than or equal to 4.5 and less than 6, it is called a moderate earthquake.

Strong earthquakes are those with magnitude greater than or equal to 6 and less than 7.

A magnitude greater than or equal to 7 is called a major earthquake.

Earthquakes with magnitude 8 or above are called major earthquakes.

Earthquake intensity: Earthquake intensity refers to the degree of damage to buildings such as ground and houses caused by earthquakes. For the same earthquake, different regions have different intensities. The closer to the source, the greater the damage and the higher the intensity; Away from the earthquake source, the damage is small and the intensity is low.

Below three degrees: people have no feelings, only instruments can record them;

Three degrees: people have feelings in the dead of night;

◢ Four or five degrees: the sleeping person wakes up and the chandelier swings;

◢ Six degrees: the utensils were dumped and the house was slightly damaged;

◢ 67 degrees: the house is damaged and the ground is cracked;

◢ 9- 10 degree: the house collapsed and the ground was seriously damaged;

◢ 10- 12 degrees: destructive damage.

The strongest earthquake

1. The earliest recorded earthquake in China: China Yaoshun era (23rd century BC), which occurred in Zhou Pu (now Zhou Pu).

2. The earthquake that caused the biggest fire in the world: September 1923, Kanto, Japan.

In the 8.3-magnitude earthquake, 366,000 houses in Tokyo with many wooden houses were burned down, and 6,543.8+0.4 million people died and their whereabouts were unknown, most of them were killed by the fire caused by the earthquake. In Yokosuka, 35,000 houses were burned down; In Yokohama, 58,000 houses were burned down.

3. The earthquake that caused the biggest flood in China: 1 July 861occurred in the south of Kangding, China.

In the earthquake of magnitude 7.5, the Dadu River was cut off due to landslide, and it burst after 10, which caused a catastrophic flood and caused hundreds of thousands of deaths.

4. The biggest earthquake in the history of the world: an earthquake occurred in Chile, South America 1960 at 9: 00 on May 22nd, with a magnitude of.

Since May of 8.9.2 1 year, there have been earthquakes within one month, with magnitude exceeding 8 for 3 times and 10 for more than 7 times. Its scale and energy release are rare.

5. The first earthquake successfully predicted in the world and achieved obvious disaster reduction effect: Chinese seismologists successfully predicted1February 4, 975 Haicheng earthquake with magnitude 7.3, which was called "a miracle in the history of earthquake science" by the world scientific and technological community.

6. The world's largest earthquake and tsunami:1On May 22, 960, an earthquake of magnitude 8.9 occurred in Chile.

7. At present, the largest earthquake recorded by instruments in the world: On May 22, 0960, an earthquake of magnitude 65438+8.9 occurred in Chile, South America.

8. Inventor of the first seismograph in the world: The first seismograph in the world (Hou Feng seismograph) was invented by Zhang Heng, a scientist in the Eastern Han Dynasty, and recorded the Longxi earthquake in 138.

9. The earliest self-built seismic network and seismic telemetry network in China:

1930, the first seismic station in China, Jiu Feng Seismic Station in Xishan, Beijing, was built under the auspices of Li Shanbang and Mr. Qin Xinling, and observation stopped after the Japanese invaders launched the war of aggression against China in 1937. 1966 Beijing Telemetry Network has built 8 substations.

10. The earthquake with the largest number of deaths:1556 65438+1October 23rd, hua county, Shaanxi Province, M 8.0 earthquake, with more than 830,000 deaths.