This Volcanic Island Suddenly Appeared In Japan. Where Did The Energy Come From?

Volcanoes can create new land masses by depositing magma, or molten rock, from the interior of the earth onto the surface. Rocks have to get very hot in order to melt. The temperature at which common rocks melt is above 600 degrees Celsius, and usually higher. Hence, as most of you probably are aware, putting a rock into a common cooking oven, stove, or fire is not going to make it melt. The very existence of volcanoes therefore implies that the interior of the earth is very hot. Current models actually predict that the temperature is around 6,000 degrees Celsius in the center of the earth, which is very hot indeed.

Where does this heat come from? After all, the earth is just a big ball of rock in mostly empty space, and if you heat up a rock and then hold it up in the air the rock will cool off pretty quickly. The heat cannot be provided by solar radiation as the surface of the earth, where the radiation is received, would then be hotter than the interior. This is obviously incorrect. Another possibility is that the heat is leftover from when the earth formed. Rocks cool, but if the initial rock is hot enough and big enough, it would take a very long time to cool. The rate of earth cooling is a relatively straightforward calculation in thermodynamics, the study of heat and energy in physics. If you assume the earth is a large uniform sphere that started off very hot and eventually cooled to the current surface temperature of roughly 25 degrees Celsius, then you come up with an age of 30,000 years for the earth! ( Link ) Lord Kelvin, who originally did this type of calculation in 1862 with different assumptions, calculated an age of 100 million years. While both these calculations make somewhat incorrect assumptions about the earth, it is also clear that neither cooling time is at all comparable to the current age of the earth, currently measured to be approximately 4.5 billion years. We can therefore rule out the idea of leftover heat from the earth’s formation as the only heat source for magma.

If the heat is not from outside (solar radiation) and cannot be fully leftover heat, there is only one possibility left: there must be a source of heat that exists inside the earth! This is actually the case. Temperature is a macroscopic quantity we assign to a material in which the atoms of the material are moving around. Higher temperatures mean the atoms of the material are moving around faster. Inside the earth there are many radioactive atoms, uranium, thorium, potassium, etc. These atoms undergo nuclear fission and emit various types of subatomic particles at high speed, which in turn hit the other atoms in the earth, cause them to start moving around, and as a result generating heat. This radioactive heat is a major source of the heat needed to melt rock in the interior of the earth. In a sense, the earth is a big nuclear reactor. Hence the island shown, a pretty large piece of real estate, is in the end possible because of nuclear reactions that happen at tiny, subatomic distances.

Basically the energy causing it, is geothermal energy. But recalling that several thermonuclear reactions occur in the earth's interior, which are exothermic the first answer is an admissible option.

Most of the energy for the activities happening inside the earth comes from fission reaction of radioactive substances found inside the core of the earth. Due to pressure created inside the earth because to nuclear activities such incident happen.