Barometric pressure at 10,000 feet deep in the sea is
760 mmHg
523 mmHg
349 mmHg
226 mmHg
The approximate barometric at sea level, the barometric pressure is 760 mm Hg; at 10,000 feet, it is only 523 mm Hg; and at 50,000 feet, it is 87 mm Hg. This decrease in barometric pressure is the basic cause of all the hypoxia problems in high-altitude physiology because, as the barometric pressure decreases, the atmospheric oxygen paial pressure (PO2) decreases propoionately, remaining at all times slightly less than 21 percent of the total barometric pressure; At sea level, PO2 is about 159 mm Hg, but at 50,000 feet, PO2 is only 18 mm Hg.Ref: Guyton; 13th edition; Chapter 44; Ation, High Altitude, and Space Physiology
General physiology