I couldn’t think of any other way to describe it, so I thought I’d look up what’s called XX on Earth.
The navel of the earth: Ayers Rock in Australia is famous. It is a huge monolith of sandstone that is over 300m high and 90% of its length is still buried. It is like a navel in terms of its size and shape. As the word “earth” is attached to it, the scale is grand.
https://worldheritagesite.xyz/contents/ayers-rock
Lungs of the Earth: There are various theories these days, but one of the most well-known is the Amazon rainforest. It seems that the Amazon rainforest is considered to be a lung because it exchanges large amounts of carbon dioxide and oxygen. Since it is an area with a lot of forest and lots of sunlight, photosynthesis is probably very active there. This activity is sometimes called the breathing of the Earth.
https://worldheritagesite.xyz/central-amazon
Heart of the Earth: This does not seem to be a well-established concept yet, but there have been expressions such as the equatorial atmosphere vibrating like a heartbeat, and the importance of the oceans to the Earth as a heart.
Kidneys of the Earth: This is what wetlands are sometimes called. The way that the sunken mud purifies water as a natural filter is likened to the way the kidneys filter waste products. The total area of wetlands, swamps, mangroves, etc. on Earth seems to cover 12 million km².
https://alj.com/ja/spotlight-by-fady-jameel/
Skin of the Earth: It could be the ozone layer or the soil. It’s like the Earth or the surface of the Earth. Leonardo da Vinci thought of water as the blood of the Earth and rocks as the bones of the Earth.
https://diamond.jp/articles/-/221653?page=2
The Earth Humming: It’s like the Earth is singing at a constant, low frequency that is too low for humans to hear. It’s the crashing of ocean waves.
https://wired.jp/2015/04/21/earth-mysterious-hum-revealed
There are also other expressions such as the temperature of the Earth, the Gaia theory approach that sees the Earth as a single living organism, and the expression “the Earth’s XX” as a poetic or metaphorical expression. For now, the common understanding is that it is the lungs and kidneys of the Earth. It was an attempt to capture the Earth in a familiar image. The Earth is magnificent. The Earth is amazing.
