Even if billions of years have passed, how can there still be magma in the center of the earth?

The Earth's crust has poor heat transfer capacity, and the outside has cooled into solid rock, but the inside is still hot and liquid. In addition, the decay of radioactive elements in the earth's core generates heat, so that the earth still has a hot liquid core (the center of the earth's core remains solid due to internal high pressure). The hot core emits heat outward, heating the mantle and keeping the upper layer of the mantle in a liquid state, which is the asthenosphere of the upper mantle.

The heat continues to transfer outward, heating the lower layers of the earth's crust into a liquid state.

This is magma.

This is because the temperature in the depths of the earth is very high, so anything here will melt quickly, so there is still hot lava.

I think the main reason is that the Earth is a huge object, and some of the things in it are the result of being renewable.

Because the temperature and pressure in the center of the earth are very high, and the heat cannot be dissipated, there is still magma in the center of the earth.

The cross-section of the Earth, the key heat transport regime within the Earth, shows its core hierarchical zoning and its approximate dedication to all the heat flowing into the Earth's interior. However, for the large planets floating in space, there is only one form of heat dissipation, that is, radiant heat, because it cannot quickly dissipate heat through thermal convection volatilization, etc., so the only way to transfer heat energy from the terrestrial radiation source to the alien planet in the form of long-wave infrared radiation source. However, some of these LWIR radiation sources will be intercepted by the air, especially by clouds and air pollutants, so not many of the radiation sources will go out.

The relative equilibrium of the Earth's temperature at this stage proves that the amount of such radiation sources is in equilibrium with the heat received by the Earth and its floor heating, otherwise the Earth's surface temperature will continue to rise or fall. As a result, the efficiency of this type of heat dissipation is almost zero for the lava rocks in the Earth's interior. Even if every underfloor heating is released, it is only milliwatts per square meter.

And that's not even counting the daily heat absorption from the sun's rays on Earth (think of dog days), even though the sun's heat doesn't really help to maintain the "human body temperature" in the Earth's core.

The ratio of area to volume is that the more large planets have, the slower the heat dissipation, because the area is accompanied by the expansion of volume, and the ratio to volume is getting smaller and smaller (the ratio of one quadratic to cubic one), which is the same reason that the larger the small animal, the more resistant it will be. Compared to sparks, the earth is much larger. The quality of the spark is earthly, and the volume is earthly, so the heat of the internal structure of the spark for billions of years has long since dissipated and turned into a dead star, and there is almost no magmatic activity underground.

The mass and volume of Earth and Uranus are similar, so the magmatic activity of the internal structure is still very active.

The internal structure conceals the thermal convection compressive strength ridge of the liquid substance and the lava rock in the core of the earth is mainly composed of ferrosilicon, while the core of the earth is essentially iron-nickel alloy. The density of this substance is large, and the circulation is much worse than that of the liquid substance composed of these cold and low-density elements in the internal structure of gaseous planets, so the thermal convection is actually not obvious, and the high efficiency of thermal conduction to the center of the earth for billions of years is relatively low. As a result, both Earth and Uranus maintain a fiery red core.

Because the interior of the earth is a high-temperature and high-pressure environment, and it is difficult to dissipate heat, the underground is still lava.

The main reason is that the core of the earth is already solid, but because the pressure on the core and the upper layers of the liquid and mantle is very high.

The main reason is that the temperature of the earth's core is as high as 5,000 degrees, and such high temperatures make the earth's core become lava.

Magma is a hot, complex silicate melt deep in the earth's crust. The physical properties of this melt are peculiar, it resembles both a hard solid and a soft liquid. Like red-hot glass, it flows and bends, but it is very hard and dense.

Thus, in Greek, the original meaning of magma meant "dough" that could be kneaded. This "dough" contains a wide variety of metallic, non-metallic, and gaseous components. Almost all the chemical elements on Earth can be found in magma.

This high-temperature molten magma is mainly concentrated in the upper mantle layer hundreds of kilometers below the surface. It was originally a very energetic substance, but it was only under the pressure of the heavy overlying rock layer that it was in a state of intense compression, and could not flow freely like a liquid. Despite this, due to differences in pressure in the Earth's crust, magma still flows up and down the Earth's interior like blood in the human body, but at a very slow rate.

Once a crack appears in the earth's crust, magma erupts violently along the cracks and shallow parts of the strata with weak external pressure, which is called a volcanic eruption.

The magma that overflowed the surface was like freshly baked molten steel, fiery red and red. It has been determined that the temperature of magma is generally between 900-120 0 and can reach up to 1300. Wherever it flowed, there was a sea of fire.

After cooling and solidifying, various volcanic lava are formed, such as basalt, andesite, rhyolite, etc. Another form is violent eruptions, forming volcaniclastic rocks. Sometimes magma fails to break out of the earth's surface, but it cools and solidifies at different depths of the earth's crust, forming various intrusive rocks, such as granite, peridotite, diorite, etc.

The minerals that were originally melted and dispersed in the magmatic rocks gradually crystallized and separated in order with the condensation of the magma, the heavy ones sink to the bottom, the light ones float on top, and the more active mineral juice volatile components can also penetrate into the crevices of the peripheral rocks to form ore veins.

The main magma accumulates in different kinds of intrusive rocks deep in the strata, often controlling specific endogenous deposits. For example, nickel ore, chrome ore, platinum group element ore, barium titanomagnetite, etc., are only found in ultramafic rocks; Tungsten, tin, molybdenum, bismuth ore and crystal, chrysoberyl, etc. should be found in the granite body and its vicinity. Agate and some iron, gold and silver ores, and many non-metallic minerals are often produced in volcanic rocks.

Because the temperature inside the earth is very high, the rocks are melted. I guess the point of your question is why the temperature is so high that it causes the rock to melt. Personal thoughts:

the movement of the earth (rotation and revolution), which leads to internal friction and an increase in temperature; Of course, there will also be a series of chemical reactions to the heat. The outer layer of the earth's crust is thick enough that the heat generated by movement is greater than the heat transferred to the surface, so the internal temperature gradually increases. When the temperature reaches a certain stage, the rock can be melted and magma can be produced.

The Earth's interior is very hot, with 900 at the bottom of the crust, 86,000 at the core mantle border, and 192,100 at the center of the Earth. Substances known in nature will melt at this high temperature, so magma is a substance that is rich in volatile gases when the existing rocks on the earth, such as magmatic rocks, sedimentary rocks, and metamorphic rocks, return to a molten state due to high temperatures.

I have answered this question many times, the energy of the earth's autobiography indirectly comes from the universe, and the direct cause of the autobiography is caused by the formation of the earth, the earth is caused by the accumulation of countless meteorites attracting each other, because meteorites have speed and different directions, they must be colliding with each other, and the energy of the earth's autobiography comes from the collision of meteorites, and the earth was a fireball when it was first formed, and it was a rock after the surface cooled slowly. The lava in the Earth's interior is evidence that the fireball did not cool down when it was formed, but it will one day.

Meteorites have already revolved around the sun before the formation of the earth, so of course they will revolve around the sun after formation, whether it is revolution or rotation, it will continue for a long time under the action of inertia.

Energy ** is the radiation emitted by the decay of radioactive materials in the earth's interior that is absorbed and converted into heat energy, and because it is in the center of the earth, the heat dissipation is very small, and today's magma layer is formed over hundreds of millions of years.

The Earth was originally a stellar remnant formed by the burning energy of a star with a mass smaller than the Sun. Later, it gradually cooled down to stone, and the stone weathered into soil. However, there is still residual heat in the core, and the residual heat is constantly dissipated from the ground, resulting in the volume of the core shrinking without thermal expansion support.

The rocky crust of the crust cannot withstand the central gravity and atmospheric pressure, and the fracture occurs**. In a longer period of time, the Earth will shrink to a smaller size and become an icy stone ball. The sea submergs all continents and freezes all day long.

Because of the temperature of the earth's core, there will still be lava under the earth, and lava cannot disappear.

Russian physicist Fedor Nivolin believes that the beginning of the formation of the earth is nothing more than a huge cold mass floating in the universe, under the influence of the sun and cosmic energy, it began to heat into a lava state, and then began to slowly cool, the surface of the earth formed a hard rock layer, but the lava under the rock layer is still in a boiling state, magma is heated and expands, forming gas to diffuse to the outside of the earth, after hundreds of millions of years of this expansion and diffusion, the center of the earth has actually become a " Huge empty shells". Nivolin believes that the main outlets for the massive diffusion of gases are at the north and south poles, where the "huge caves" that can still be clearly seen are clear geological evidence.

Because the earth's crust is always in motion and there are a lot of volcanoes, the ground is full of lava.