Help please , questions from

[brenda]

my 10 year old nephew----

1. Why does the earth not collapse inwards , as people dig things outlike coal and oil.And as the weight on the surface increases with more buildings and people.?
2.If you are digging downwards in say a mine, does it get warmer the further down you go.?

Please help if you can .TIA Brenda.

[mollykins]

Yes it gets warmer the further you get, miners deep down sometimes have to wear rpotective clothes. i can't explain number 1 though.

[mollykins]

*protective* i meant.

[factor-fiction]

Miners do wear protective clothing but I thought that was normally for reasons other than excessive heat. Yes it does get warmer but I'm not aware it gets significantly warmer at the sort of depths miners go, although it does become a factor for the world's deepest mine which is 3.6km deep and temperature is 55 degrees C. At the centre of the earth - that's over 6000km down - the temp is around 7000 degrees C ..

[brenda]

Thanks all for your help.Brenda.

[paddiez]

Mines do collapse. Go to Johannesburg and you will feel tremors,large ones ,as the older shafts collapse. Happens often.

[wildwood]

Quote from universe.com

"The deepest hole ever dug was the Russian Kola Superdeep Borehole. Started in 1970, the hole eventually reached a depth of 12.3 km. They eventually had to quit because temperatures in the hole became too hot to go any further. Other plans are in the works to bore into the crust in the ocean, where the thickness is much less."

[rov1200]

I've often wondered why we need to set up costly industrial plant to produce energy when we have a source of heat energy sitting below us waiting to be tapped?

[tamborine]

1. water infills holes & mines. What comes out remains the same in weight. As there are new-borns there are equally deaths; all is balanced and re-generated.

[Canary42]

Collapses into holes are not unknown - one example appears at ...

http://www.youtube.co...PZgq8&feature=related

Other examples can be found searching Youtube

[Old_Geezer]

Check out the volcanoes. The pressure down below is so great things are trying to push out, not fall in. That said, minor excavations in the crust can collapse if not supported and maintained.

[Old_Geezer]

You can indeed arrange to get heat out of the ground to heat/power your house. But the question is whether it is financially viable to make that sort of investment. No doubt it's time will come.