So, I was playing around with some calculations, in particular air pressure calculations. If Mars has a very deep molten core, and given that it's pretty cold there, then it's arguable that you could dig to some really deep depths with boring machines. Pressure should increase as you go down, just like it decreases as you go up. So could you dig deep enough to reach a depth where the atmospheric pressure would be suitable to human survival (assuming the temperature doesn't get too high and you have a breathing system)?
The height on Earth where supplemental Oxygen is needed is generally considered to be around 26,000 feet. I put this into an atmospheric calculator and it came out at about 5 psi (down from 14.7 at see level). I then played with the calculator to see how deep you would need to go to reach 5 psi on Mars starting from surface level pressure of 0.095 psi (assuming the calculator still reflects close to reality on such a calculation). Assuming I did this all correctly, you would reach 5 psi on Mars at a depth of about 150K feet, which is about 28 miles. Open question is what would the temperature be at this depth? And what would the material at this depth be? And will using the calculator in this manner, something it was probably not intended for, actually provide a close to realistic result?
Regardless of these questions, it seems at least viable for examination whether or not you could create a reasonable habitat by digging deep into the depths of Mars. A cave system at the right depth would provide increased pressure, increased temperature, and increased protection from radiation.
The height on Earth where supplemental Oxygen is needed is generally considered to be around 26,000 feet. I put this into an atmospheric calculator and it came out at about 5 psi (down from 14.7 at see level). I then played with the calculator to see how deep you would need to go to reach 5 psi on Mars starting from surface level pressure of 0.095 psi (assuming the calculator still reflects close to reality on such a calculation). Assuming I did this all correctly, you would reach 5 psi on Mars at a depth of about 150K feet, which is about 28 miles. Open question is what would the temperature be at this depth? And what would the material at this depth be? And will using the calculator in this manner, something it was probably not intended for, actually provide a close to realistic result?
Regardless of these questions, it seems at least viable for examination whether or not you could create a reasonable habitat by digging deep into the depths of Mars. A cave system at the right depth would provide increased pressure, increased temperature, and increased protection from radiation.