The cause of volcanic eruption

Volcanic eruption is a very serious natural disaster, often accompanied by earthquakes. The following is the information I have compiled for you about the cause of volcanic eruption. Let's have a look!

The cause of volcanic eruption

The volcano stopped erupting? Fire? This mountain spews out a high-temperature viscous substance called magma. The scene when the volcano erupted was spectacular. Usually magma is tightly wrapped in the earth's crust. Because of its extremely high temperature and great pressure from the earth's crust, whenever cracks appear in the thin earth's crust, magma will rush out of the ground violently.

When the volcano erupts, with the earth-shattering roar, stones fly and roll, and fiery magma spews out of the ground like a fierce dragon, devouring everything around. At the moment, dozens of miles in Fiona Fang are shrouded in thick smoke. Sometimes, due to volcanic eruption, a mountain can be erected instantly on the flat ground, such as Kilimanjaro and Coto Paxi near the equator. Sometimes, it can devour whole villages and towns in an instant.

Volcanoes form below the surface, and the deeper the place, the higher the temperature, about 20 miles deep, which is high enough to melt most rocks. When the rock melts, it expands and needs more space. This material melted by high temperature will rise along the cracks caused by the uplift. When the pressure in the lava tank is greater than the pressure of the rock above it, it explodes outward to form a volcano.

Signs before volcanic eruption

Understand the symptoms before volcanic eruption and take timely measures before volcanic eruption. Signs before the volcanic eruption are:

(1) Where the volcano is about to erupt, irritating acid rain, loud rumbling or plumes of steam from the ground are all warning signals.

* Signs before volcanic eruption. There are usually some signs before a volcano erupts. Knowing these signs can save your life at a critical moment. surface lift

(2) Before a volcano erupts, there are often microseisms, the volcanic crust breaks and the volcanic vibration increases, indicating that the volcano is close to eruption.

(3) The nearby ground temperature, air temperature and water temperature rise, and the ice and snow melt. The temperature of groundwater will be higher than usual, or abnormal. Many tall volcanoes are above the snow line all the year round. If the ice and snow on the volcano melt, it indicates that it will erupt.

(4) Animal abnormality. Deep-sea fish swim to shallow water and find strange fish or special invisible fish or other deep-sea animals in a certain area; Animals living on the ground and underwater suddenly appear or die. 3. The salinity of the ocean changes and the fish family swims abnormally.

At present, human beings have no ability to control volcanic activities, and strengthening forecasting is the only way to prevent volcanic disasters. Scientists' research on volcanic eruptions often benefits from some mutations in animals and plants. Many animals often flee before a volcano erupts, as if they knew that disaster was coming. There is a wonderful plant in Java, Indonesia, which will bloom before the volcano erupts. Local residents call it "volcano warning flower".

Volcanic formation

According to the theory of plate tectonics, the movement of plates is caused by thermal convection in the asthenosphere inside the earth. When plates push each other, one side with higher density will fall below the other side, which is called subduction, and the belt area where subduction occurs is called subduction zone or convergent plate boundary. The high temperature underground will melt the hidden plates and form magma. Magma rises slowly by buoyancy, and finally converges into a magma chamber, and magma chamber is the place where magma is stored at the bottom of the volcano. When the gas pressure in the magma accumulates to a certain extent, the volcano erupts. For example, most volcanoes in the Pacific Rim are of this type.

Some volcanoes are distributed at the boundary between plates, that is, the belt-shaped area where the two plates are separated. In this area, high-temperature mantle material will rise and form submarine volcanic mountains, which are called mid-ocean ridges.

The movement of hot spots forms a chain of volcanic islands, and some volcanoes are not located at the junction of plates, such as the Yellowstone composite crater in the United States and the Hawaiian Islands. Volcanologists say these volcanoes are located? Hot spot? Let's go At present, the formation mechanism of hot spots is not clear, but scientists generally believe that hot spots rise from the bottom of letters? Hot column? Because. When the plate moves horizontally on a hot spot, a series of volcanoes will be produced. After this continuous action, a series of volcanic islands will be formed, and the farther away from the hot spot, the older the volcano is.