1. According to the official Weibo news of the National Seismological Network, China Seismological Network officially determined that on June 29th, a magnitude of 3.4 occurred at Shuangfeng County, Loudi City, Hunan Province (27.57 degrees north latitude, 1 12.07 degrees east longitude) 10, 12.02.

At 2.20 19: 48, 16 seconds, an earthquake of magnitude ML3.2 occurred in taojiang county, Yiyang city, Hunan province (east longitude 1 12.04 degrees, north latitude 28.56 degrees) with a focal depth of 7 kilometers.

3. Changde earthquake 163 1.

According to historical records, the earthquake caused serious casualties and property losses. According to the analysis of the ancient earthquake relics recently discovered in Changsha, there have been at least two earthquakes of magnitude 7 or above in Hunan. There are three moderate earthquakes recorded in Changsha in history. Changsha is one of the key cities for monitoring and defending the national 13 earthquake determined by the State Council.

Extended data

Earthquake precursor phenomenon

All kinds of signs in nature that may be related to the preparation and occurrence of earthquakes before earthquakes are called earthquake precursors. There are usually two types:

Micro-precursor: the changes before the earthquake that are not easily detected by human senses and can only be measured by instruments. For example, the deformation of the ground, the change of the earth's magnetic field and gravity field, the change of the chemical composition of groundwater, the activity of small earthquakes, etc.

Macroscopic precursors: earthquake precursors that can be perceived by human senses. Most of them are near the earthquake. Such as fluctuation and turbidity of well water, abnormal animal behavior, ground sound and ground light, etc.

1, groundwater anomaly

(1), abnormal changes of water level and water quantity. For example, during the dry season, the well water level rises and the spring water volume increases; In the rainy season, the water level drops or the spring stops flowing. Sometimes the well water flows by itself and sprays by itself.

② Changes of water quality. For example, well water and spring water change color, taste (such as bitter and sweet), turbidity and odor.

③ The change of water temperature. The water temperature exceeds the normal range.

(4), others, such as flower bubbling, spouting, borehole wall deformation, etc.

2. Biological abnormality

Animals are "living instruments" for observing earthquake precursors, and various anomalies often appear before earthquakes;

The abnormal behavior of animals in earthquake precursors indicates the coming disaster to people. It has been found that hundreds of animals have some abnormal behaviors before the earthquake, among which there are more than 20 kinds of common abnormal reactions. The most common animal abnormal phenomena are:

Panic reaction: such as large livestock not entering the circle, dogs barking, birds or insects flying around, abnormal group migration, etc.

Inhibitory abnormality: if my behavior becomes slow or in a daze, I will be at a loss; Or refuse to eat, etc.

Changes in living habits: for example, hibernating snakes come out of holes, mice are not afraid of people during the day, and frogs go ashore in large numbers.

3. Electromagnetic anomalies

Electromagnetic anomaly refers to the failure of household appliances such as radios, televisions and fluorescent lamps before the earthquake. The most common phenomena are radio failure, cell phone signal weakening or disappearing, and electronic alarm clock failure.

4. Earth Voice

Before the earthquake, there were often sounds coming from deep underground, which was the "earth sound". Earthquakes usually occur minutes, hours, days or earlier before earthquakes; It appears at most a few minutes before the earthquake is about to happen.

The sound of the earth sound is different and changeable from the familiar sound. Such as: "like a train running out of the ground", "like a barrage of stones", "like the roar of machines", "the roar of the wind", "the friction between stones" and so on. However, sometimes the voice of the earth is not easily distinguished from the distant wind, thunder and the roar of machines.

5. Floor lamp

Terrestrial light is also a macroscopic phenomenon before the impending earthquake, which was observed before many earthquakes in China. They usually appear before or during the impending earthquake, and some appear a few hours or earlier before the earthquake.

There are many colors of the earth's light, including red, yellow, blue, white and purple, and some are like electric fire. They have different shapes, such as strip lights, sheet lights, spherical lights, column lights, fire lights and so on.

Terrestrial light generally appears for a short time and is not easy to observe. Ground light is also difficult to identify because its shape and color are sometimes similar to welding light and lightning.

Reference People's Network-A magnitude 3.4 earthquake occurred in Shuangfeng County, Loudi City, Hunan Province, with a focal depth of 8 kilometers.

Reference materials Seismological Bureau of Hunan Province-Seismological Bureau of Changde City actively handled the Taojiang earthquake with M = 3.2 in Yiyang.

Refer to Baidu Encyclopedia-163 1 Changde earthquake.