Why do you need to understand the influence of volcanoes?

There is a "liquid zone" between 100 and 150 km under the crust. In this liquid zone, there is a molten silicate substance containing gas volatiles at high temperature and high pressure, that is, magma. Once it rushes out from the weak part of the earth's crust, a volcano is formed. Volcanic eruption can eject a variety of substances, among which there are generally rocks, debris and volcanic ash crushed by blasting. Among the ejected liquid substances, there are generally lava flows, water, various aqueous solutions and mud flows mixed with water, debris and volcanic ash. Among the ejected gas substances, there are usually water vapor and oxides of carbon, hydrogen, nitrogen, fluorine and sulfur. In addition, in volcanic activities, visible or invisible light, electricity, magnetism, sound and radioactive substances are often ejected, which can sometimes kill people, or make power and instruments fail, resulting in plane and ship crashes.

Although volcanoes often bring great disasters to mankind, they are not without their merits. The utilization of volcanic resources can also bring us fun and convenience in life. Generally speaking, volcanic resources are mainly reflected in their tourism value, geothermal utilization and volcanic materials. Volcano and geothermal are twin brothers. Where there are volcanoes, there are geothermal resources. Geothermal energy is a cheap and pollution-free new energy, so it has been widely used. Now, from medical treatment, tourism, agricultural greenhouses and aquaculture to civil heating, industrial processing and power generation, we can see the application of geothermal energy. People have calculated geothermal energy in Camet volcanic area, where there are thousands of natural steam and hot water vents, with an average of 20,000 cubic meters of hot water and steam per second, which can bring out 40 trillion calories from the earth's interior in a year, equivalent to 600 million tons of coal. Iceland is located in a zone with frequent volcanic activities. The exploitable geothermal energy is 45 billion kWh, and the annual power generation can reach 7.2 billion kWh. People there make good use of this resource. Although only 7% of it has been developed at present, it has brought many benefits to local people. Among them, three geothermal power stations around Reykjavik provide hot water and electricity for 6.5438+0.5 million Icelanders, and 85% residents in Iceland use thermal energy for heating. Geothermal resources are clean and sanitary, which greatly reduces the import of oil and other energy sources. Since 1975, the air quality in Iceland has been greatly improved. Icelanders are also good at improving the utilization efficiency of geothermal resources, including planting vegetables and flowers in greenhouses, establishing all-weather outdoor swimming pools, and laying hot water pipes under sidewalks and parking lots to speed up the melting of snow in winter. At present, more than a dozen countries in the world are using geothermal energy to generate electricity. Yangbajing, Tibet, China has established the largest geothermal test base in China and achieved good results.

The most powerful and spectacular volcanic eruptions often occur in subduction zones. The volcano here may erupt again after hundreds of years of silence, and once it erupts, its power is particularly fierce. This kind of volcanic eruption often brings disasters to mankind.

1, which affects the global climate, a large amount of volcanic ash and volcanic gas emitted during volcanic eruption have a great influence on the climate. Because in this case, dark days, storms and even mud rain will bother local residents for months. Volcanic ash and gas are sprayed high into the air, and they will spread far away with the wind. These volcanic materials will block the sunlight and cause the temperature to drop. In addition, they will filter out some wavelengths of light, making the sun and the moon look like they are covered with a halo or have strange colors, especially at sunrise and sunset, which can form a strange natural landscape.

2. Destroying the environment, a large amount of volcanic ash ejected by volcanic eruption combined with heavy rain to form debris flow, which can destroy roads and bridges, flood nearby villages and cities, and make countless people homeless. Mud formed by soil and rock fragments can flood the whole city. Although the rocks are covered by volcanic ash clouds, when the volcano just erupted, you can still see huge rocks spewing into the air.

3. Reviving volcanic eruption has a far-reaching impact on the natural landscape. Land is the most precious resource in the world, because it can breed all kinds of plants to support everything. If volcanic eruption can cover farmland with volcanic ash less than 20 cm thick, it is really a blessing for farmers, because these volcanic ash are rich in nutrition and can make the land more fertile.