The subterranean composition of our planet is actually far more like a sponge. It may be able to support multiple air pocketed ecosystems deep beneath the surface. We already know that there are entire oceanic reservoirs of water underground. There is also a giant subterranean-underwater network of caverns that could act as a funneling mechanism for water transmission through a sponge like Matrix of interlocking tunnels that expand and contract during plate-tectonics. You could imagine how geomagnetism may also play a role – if the Sun alters our planets electromagnetic field strength than the underground plate-tectonics may also behave in a different way.
In other words the Earth may be more like an air-pocketed sponge that periodically exchanges matter with the surface world in response to fluctuations in electromagnetism and gravity. Rather than how the Earth is usually depicted underground – as a uniform decline of solid or liquid layers that alter in composition as you increase in depth. In fact we’re finding that the “molten iron core” is actually not uniform at all, it is highly lop-sided. However it is also important to remember that the layered and honeycomb/sponge like models of the Earth are not necessarily mutually exclusive.
The Earth for example could be sponge-like WITH a layered quantization of various states of matter including perhaps even plasma. The reason why a sponge like honeycomb structure is so pertinent is because it suggests that an entire air-pocketed ecosystem may be able to thrive deep within one of these subterranean air pockets. Imagine finding complex forms of life we didn’t even know existed – on our own planet! Or how about transforming an air pocket for human habitation? People often look up for an an escape vector, but maybe we need be looking down as well. Maybe we should “distribute our assets” more equally.
We already know that some microscopic lifeforms can feed off of the irradiating heat from a geothermal vent. That is why they have begun hypothesizing the existence of extraterrestrial life underneath the ice sheet of watery moons like Europa and Enceladus. They justify that claim by reasoning that if there is indeed a wide-spanning ocean deep beneath the icy surface then there may also be geothermal ventilation that could support organic life. In this scenario you might have an ecosystem that has primarily evolved shielded from a vast majority of electromagnetic radiation. The same could be said for the underground caverns of water and air within the Earth.
Organisms that have evolve primarily underground may even end up outlasting forms of organic life on the surface. Remember how the outside of Earth has to contend with the entire solar system and galaxy at Large. Whether it be an asteroid impact, coronal mass ejection, galactic cosmic radiation or perhaps even extraterrestrial intervention. How about hurricanes or tornados? It stands to reason that an organism evolving underground would have the added benefit of remaining shielded from most of the natural catastrophes that occur on the surface. However an underground air pocket would not be invulnerable. It might be at risk of collapse, shaking or flooding from the underground earthquake activity of plate-tectonics.
It’s interesting to note how often people mention how space exploration might lead to colonization but rarely acknowledge the Earth as a potential candidate for future exploration and settlement. It is much closer to home after all and you do not have to travel tens of thousands of miles. There are plenty of advantages that may arise from discovering ecosystems underground that you might not expect by the way. If there is a new form of plant life deep beneath the surface we might be able to create new medicine from there constituent organic compounds.
Look at it this way – we’ve already discovered the existence of microscopic lifeforms very deep beneath the surface of Earth. Furthermore we know that some plants can feed off rock. The point being that primordial life-forms such as this may have acted as a catalyst for the evolution of even more complex forms of life that have yet to be discovered. The reason why that is relevant to humanity is that if life can survive underground, WE may be able to as well. The air pockets within the interlocking cave system likely reconnect with underground aquifers at certain points along their progression. Perhaps an area such as this would be a good place for a colony.
With that being said, if you had a large enough air pocket underground with a completely different atmospheric composition then there is on surface, any form of life you might find here could be indiscernible in their alien-like nature from an extraterrestrial species. Organic life on Titan for example, a moon of Saturn might have to swim about in a Lake of methane and breathe Ammonia because it is so far away from the sun that methane liquefies and water freezes. The same could be said for an isolated air pocket that has a different average temperature and/or elemental composition then the surface world. In fact that is the actual science of space colonization: We create a sealed structure that has a composition, humidity and temperature similar to Earth. So why couldn’t this also happen underground?
It’s interesting to note how scientists are now declaring that organic life throughout the solar system may have been able to survive for longer deep beneath the surface of a planet. Such as within a network of lava tubes like on the Moon and Mars. That is good news for the existence of extraterrestrial life and the future of space colonization, however beyond that it also means that it is far more likely that life could exist within in a network of underground tunnels here on the Earth. The benefit to underground exploration and settlement is that it could simulate the required technological instrumentation for colonization of lava tubes in outer space. It may also give us some much needed practice in handling forms of organic life that are analogous to extraterrestrial life in there alien-like nature.
With that being said now let’s consider the force of gravity. We know for example that there is a slight differential in the amount gravitational force that is somehow related to plate-tectonics. It may also be due to atmospheric perturbation from magnetic, and crystalline outcroppings underground. The question being – could the same thing happen within an underground air pocket? If the area is surrounded by some kind of partially magnetized, piezo-electric mineral substrate is it possible that an underground air pocket might have a different gravitational field strength? In that case the environment might be almost indiscernible from an alien world.
Another reason why we should further explore the underground cave system of planet Earth is that it could lead to an expansive area that is far easier to colonize then outer space. In other words, if you want to build a colony underground the amount of variables that you have to contend with are far more limited. Find the right air pocket next to a subterranean water aquifer and you might just have to seal off a few areas and pump oxygen in. You could imagine perhaps an underground colony powered by geothermal energy. Furthermore if organic lifeforms within the air pocket were similar enough to the surface we may even be able to rely on them for purposes of nourishment and medicine.