What will happen after Mount Fuji in Japan?

According to the Japanese current affairs agency reported on the 19th, the Japanese Police Department has begun to prepare for the possible eruptions of Mount Fuji. People familiar with the matter said that the Japanese Police Department distributed the dust -proof mask to the local police department. The Police Department believes that if Mount Fuji erupts, the volcanic ash may not only fall in the area near Mount Fuji, but also in the Tokyo Metropolitan area.

Why can Mount Fuji erupt? What impact may it bring?

Mount Fuji broke out last time, it has been 315 years

Mount Fuji is 3,776 meters high, located in the south of Benshu Island, Japan. It is about 80 kilometers from Tokyo in the east. It is the highest peak in Japan and a living volcano.

In recent years, there have been news reports that Mount Fuji has begun to have activities. In the impression of Zheng Jingyun, a researcher at the Institute of Geographical Sciences and Resources of the Chinese Academy of Sciences, Mount Fuji last time was still in the early 18th century.

According to historical records, the last eruption time of Mount Fuji was in 1707, 315 years. Data show that the volcano erupted for 16 consecutive days, and thousands of square kilometers of volcanic ash peripherals permeated, and the entire Edo region (now Tokyo) was almost no day, and the smell of fire and sulfur was filled everywhere in the air.

"The eruption of Mount Fuji in 1707 may have a greater impact on Japan, and its impact on the global climate is not particularly typical." Zheng Jingyun told the Science and Technology Daily reporter.

The volcano, who has been sleeping for more than 300 years, why may it "wake up" this time?

In response to this issue, Chu Guoqiang, a researcher at the Institute of Geology and Geophysics of the Chinese Academy of Sciences, said that due to internal geological activities, volcanic eruption is normal.

If eruption, how does it affect our country?

Zheng Jingyun introduced to reporters that if Mount Fuji erupted, it would bring serious air pollution to the local area. The volcanic ash will not only affect human health, but also seriously affect the local water resources and ecological environment. At the same time, the large amount of high temperatures brought by volcanic eruption flow to the ground, and it will also destroy the surrounding geological and ecological environment.

"However, the direct impact of Mount Fuji on our country may not have a little significant impact." Zheng Jingyun explained that this is because my country is in the "upper wind zone" of Mount Fuji. The wind blows from west to east. However, if the eruption of Mount Fuji is a "strong volcanic eruption", it may affect my country's cooling and rainfall through the atmospheric circulation.

Strong volcanic eruption refers to the eruption incident of VEI ≥ 4 in the volcanic explosion index. The VEI index reflects the size of the volcanic eruption. The index is measured by the overall accumulation of volcanic substances generated by a eruption. There are 8 levels, namely micro (level 1), small (level 2), medium 3 (level 3 (level 3) ), Zhongda (level 4), large (level 5), large (level 6), huge (level 7), super (level 8), each increased level, the overall overall accumulation increased by 10 times.

Zheng Jingyun said that a strong volcanic eruption injects a large amount of sulfur -containing gas into the atmosphere. These gases form a sulfide gas solid in the lower part of the flat flow layer through a series of chemical reactions, and the mix of gas solids and water vapor to form volcanic clouds, which affects cooling and rainfall. "In layman's terms, this group of clouds block solar radiation, which causes cooling. If its water vapor is sufficient, it will bring rainfall."

Related studies have shown that the volcanic cloud will spread rapidly within 2 to 3 weeks with the atmospheric circulation, affecting regional and even global climate. Under normal circumstances, a strong volcanic eruption will cause the average temperature of the hemisphere or the global surface to fall by about 0.3 ° C within 1-2 years.

The scope of influence is smaller than the outbreak of volcanoes in low latitudes

Considering the atmospheric circulation movement, Zheng Jingyun said that Mount Fuji is located in the middle latitude, and the impact of eruption is generally smaller than the volcano in the equatorial area. The atmospheric movement in the equatorial area from low latitudes to mid -latitude to high latitudes, there is a phenomenon of "three circles circles". The volcanic eruptions such as volcanic ash and air -solid oscillated can reach farther places, which will affect the area. Essence The volcanic eruption logistics in the mid -latitude zone is not easy to flow to low latitudes, and the influence range is small.

"Specific impact, but also depends on the eruption." Zheng Jingyun said.

Zheng Jingyun also shared with reporters a study of a significant impact of volcanic outbreaks in the low latitudes -Tanbola volcanic eruption.

In April 1815, the Tanbola volcanic (located at 8 ° 15 ′ south latitude) near the equator, the VEI index was 7, which greatly affected the world climate. The volcanic clouds caused by eruption weakened the solar radiation energy reaching the ground. Low temperatures caused great apologies for major crops such as rice and buckwheat in 1815-1817 in my country. In addition, in the same period, Europe and North America were generally cold and famine. In 1816, it was also called "the year without summer".

In fact, the cooling intensity of the strong volcanic eruption of different latitude is significantly different. Some studies have pointed out that 1-2 years after the eruption of strong latitudes, the temperature in my country is basically declined, and there are significant regional and seasonal differences in the cooling intensity.

In addition, in the third year of the strong volcanic eruption, secondary cooling phenomena also appeared in some areas, and the decline even exceeded the first time.

Source: Science and Technology Daily WeChat account

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