Its average depth is about 3,688 meters (12,100 ft), and its maximum depth is 10,994 meters (6.831 mi) at the Mariana Trench. Nearly half of the world's marine waters are over 3,000 meters (9,800 ft) deep. The vast expanses of deep ocean (anything below 200 meters or 660 feet) cover about 66% of Earth's surface.
hyperventilation. 1. increase of air in the lungs above the normal amount. 2. abnormally prolonged and deep breathing, usually associated with acute anxiety or emotional tension. A transient, respiratory alkalosis commonly results from hyperventilation. More prolonged hyperventilation may be caused by disorders of the central nervous system, or by drugs.
hyperventilation. abnormally fast and deep breathing, the result of either an emotional state or a physiological condition. Emotional causes include acute anxiety and emotional tension, such as in nervous, anxious patients who may have other functional disturbances related to emotional problems.