While researching geothermal energy, I learned that there are many ecosystems underground. There is as much life underground as there is on the surface, which is teeming with life, or even more. Apparently, many life forms have been found several thousand meters underground inside the Earth. The area inside the Earth where life can exist is said to be twice the volume of the ocean, and it is possible that about 70% of the microorganisms on Earth exist there.
Still, it’s amazing that life can continue in an environment without sunlight and where temperatures are higher than the Earth’s surface. Naturally, it seems to be a very different ecosystem from that on Earth. There are microorganisms that can withstand 120 degree hot water, microorganisms that use rocks as an energy source, and microorganisms that get their energy from methane. It seems to be like a vast forest of living organisms.
https://www.afpbb.com/articles/-/3201455
In addition, deep underground there are microorganisms that eat coal and produce natural gas, and in the groundwater of granite 300 meters underground there are microorganisms that breathe using sulfuric acid and the radioactive element uranium. So there are organisms that breathe using uranium. The diversity of life is amazing. It may be that the activities of living organisms underground are what produce our many natural resources.
https://www.aist.go.jp/aist_j/press_release/pr2016/pr20161014/pr20161014.html
https://www.jaea.go.jp/02/press2017/p17090901
These underground conditions seem to be similar to those of the early Earth before photosynthetic organisms appeared. Therefore, some believe that by studying organisms underground, we may be able to find clues about early Earth organisms. In particular, since the conditions underground may not have changed much since ancient times, it is possible that organisms underground may also be living in the same form as they have since ancient times. Indeed, the underground, including the strata, seems to be full of history. We look forward to new discoveries underground.
Also, just as there is groundwater, there is a theory that there is a large amount of water underground. Some say that there is an ocean underground, and that the mantle holds a large amount of water, about five times the amount of the ocean. The Earth holds quite a lot of water, doesn’t it? If there is that much water, it makes sense that there is so much life underground. This underground water must be circulating on a grand scale due to crustal movement and other factors.
https://natgeo.nikkeibp.co.jp/nng/article/news/14/1
And, although it may sound a little strange, it seems that there are mountains inside the Earth. A series of huge mountains stretches along the boundary between the upper and lower mantle, about 660 kilometers underground, and some of them are taller than Mount Everest. The underground discoveries are on a grand scale.
https://natgeo.nikkeibp.co.jp/atcl/news/19/032700188
There are mountains and oceans underground, and it seems there is also a forest-like ecosystem of living organisms. We don’t usually see the underground, and it is full of mysteries, but it is believed that the activities underground allow the activities on the surface to exist. The underground is amazing. The Earth is amazing.
