How thick is the earths crust? Would 300 miles be close at all....?

Question

and are there people like bigfoot living in dark tunnels under the crust of the earth?????????

Answer 1

Matahari got it right. Although I agree that there are no Bigfoot in tunnels deep within the earth, I do believe there is likely a group of methane eating, methane producing bacteria (Archea) that live many kilometers below the surface. Some deep boreholes have encountered them. They survive not off the sun but off chemical energy similar to the life found at at deep sea vents. I believe they are likely not connected at all to photosynthesis. There aren't really any tunnels deep within the earth. The pressures just are not conducive to tunnels being stable and lasting very long. Temperatures at 5 miles down would be well over a hundred degrees and probably around 150 degrees Fahrenheit.

Answer 2

As noted, the crust is anything from about 8km to 70km or so. But beneath that crust, the earth is just a solid as above it. That is the beginning of the "mantle". But although your 300 miles is off target for the crust, there is a zone at about 120km where the rock is much weaker. The rock gets hotter as it gets deeper, reaching tempreatures that would easily melt rock at the surface. But pressure also increases with depth, so the melting point of the rock increases, keeping it solid. But at this weak zone, the temperature and the rock melting point come close, so the rock is "softened". It is on this weak layer that the plates move. The crust sit atop the plates, and goes along for the ride.

Below the weak layer is more solid mantle, though it is still able to creep, very slowly. About 3000km from the centre, there is a sharp change to the core, known to be liquid and deduced to be made of iron. In the centre of this a ball of solid iron about 1000km across.

Answer 3

Yes and no, in mountanous regions the thickness of the crust is increased, but this to tops about 90 miles; normally it settles between 25 and 50km, depending on the geology of the land above.

There are no proof of people living in tunnels under the crust; even if they did they would have to be pretty hardy, the tempurature increases by 30 degrees C for every kilometer you go down (so by the time you got to the end of the crust the tempurature would exceed 750 degrees C) also with no sunlight complex life would be very difficult.

Hope this helps

Answer 4

The earths crust averages about 40km thick which is about 30 miles but can be up to 70km in some areas.

Answer 5

Nope, thats not close at all. The crust under the oceans is only about 3 miles thick and continental crust can be up to 40.3 miles thick.

Answer 6

The earth's crust is either oceanic (the bit under the oceans) or continental (the bit under the land masses).

The oceanic crust is uniformly 7 km thick, give or take one kilometer.

The continental crust varies from 40km (usual thickness) to 70km (under the Himalayas and Andes).

Hope this helps.

P.S. Re the Bigfoot Thingys...... dunno!

Answer 7

As far as critters living deep in the dark tunnels, as prof. Jack noted, there is a distinct lack of sunlight deep in the Earth.

For a race of bigfoot like critters to dwell deep in the Earth, they would need to feed on something. All life on Earth that we know of requires an input of energy to survive.

There are a few critters that are able to make a living deep in the darkness, but they are few and far between, and tend to be very small and also have exceedingly slow metabolisms to survive on the meager energy available in their ecosystem.

Many of the critters survive by processing the energy brought into caves in the form of bat poop. Fungi and insects can turn the poop into energy, and they in turn support a small community of predators and parasites.

There are a few types of bacteria that have managed to find alternative energy sources to sunlight deep underground. Some are able to convert the chemical energy in salts into food energy, and a few others use sulfur compounds. One type, sometimes known as snotites, essentially form greenish oozes of sulfuric acid within the rocks deep in caves. This green slime breaks down rock and uses the chemicals for energy, and may be far more important in the formation of cave systems than anyone realized.

Some very small, very slow and very pale critters can eke out a living feeding on these unusual bacteria.

But for an entire population of large, high-metabolism creatures like any kind of mammal to survive deep in the Earth would not be possible. They would need far more energy than is available down there.

I'd believe there were Horta down there before believing there's a whole society of bigfoots.

Answer 8

I asked a piece of earths crust what two plus two is, it couldn't give me the answer, how thick is that!

Answer 9

More like 40 to 60 km (25 to 40 miles) and no, no people or myths.

Answer 10

Jeez, 300 miles is way off... thickest places are 22 mi. and thinnest are 5 mi.

And bigfoot needs Spanish lessons (I dunno why).