Hello morsey2002 and thank you for the question.
So you have Taphephobia ?
"Taphephobia: Fear of being buried alive."
http://www.bbc.co.uk/dna/h2g2/alabaster/A428014
Assuming you donīt die from the terror of realizing that you have been
buried alive, you would almost certainly die from asphyxiation.
"These Herculean achievements are rendered suspect not only by the
decrepitude and weakness customarily associated with people who have
been ill enough to have been thought dead, but by the fact that a
person buried in an airtight coffin would suffocate after about an
hour.)"
http://archive.salon.com/books/feature/2001/03/07/buriedalive/index4.html
How common was it to be buried alive?
"In 1896, T.M. Montgomery, who supervised the disinterment and moving
of the remains at the Fort Randall Cemetery, reported that "nearly 2%
of those exhumed were no doubt victims of suspended animation."
http://www.snopes.com/horrors/gruesome/buried.htm
Not a very authorititive site but.........
"I estimate you have about thirty minutes before you run out of air."
http://elfwood.lysator.liu.se/libr/d/r/drewwin2/abominatio.htm.html
"I did a quick calculation in my head to see how much air per square
inch I had, give or take a few minutes, and would probably run out of
air in about an hour and 18 minutes."
http://aenai.steelsong.com/ebonydove/Magic10.htm
---------------------------------------
Letīs do our own calculation!
This casket (the zenith):
http://www.foresightfamily.com/FSF-caskets-lgvnp.htm
has a cubic capacity of 29,704 cubic inches which = 17.18 cubic feet
An 'average' human is about 0.2 cubic meters
http://www.nctimes.net/~mark/bibl_science/bible-science.htm
"the body volume of a person is about 7 cubic feet"
http://www.oznet.ksu.edu/library/grsci2/af170.pdf
So, 7 cubic feet = 12,096 cubic inches
So 17.18 cubic feet - 7 cubic feet = 10.18 cubic feet of air left to
breath with a person inside the coffin.
"Humans respire at a normal rate of 12 breaths per minute, inhaling a
volume of about 0.5 liters per breath, or 360 liters per hour. The
normal uptake of oxygen in the lungs is about 15 liters per hour of
oxygen (about 0.3kg per day), only 20% of the oxygen available in the
air in the lungs."
http://www.mas.ncl.ac.uk/~sbrooks/book/nish.mit.edu/2006/Textbook/Nodes/chap01/node7.html
10.18 cubic feet = 288.29 litres of air
Given that when we breath normally we breath 360 litres per hour, I
would imagine that under the stress of realizing that you had been
buried alive you would at least double that ammount. However, we must
remember that the air that we exahale is still 'breathable' up to a
point, and so as a 'ball park figure' I think an hour is probably
fairly accurate (But what an hour!)
(If anyone would like to have a go at producing a more accurate
figure......be my guest :)
Thank you for the intriguing question!
Best regards
THX1138
Search strategy included:
"buried alive" "out of air"
://www.google.com/search?q=++%22buried+alive%22++%22out+of+air%22&hl=en&lr=&ie=UTF-8&as_qdr=all&start=50&sa=N |