Oceanic trench the level of the surrounding oceanic floor. The greatest ocean depth measured is in the Challenger Deep of the Mariana Trench, at a depth of below sea level. Oceanic lithosphere moves into trenches at a global rate of about 3 km/yr. There are approximately of convergent plate margins, mostly around the Pacific Ocean—the reason for the reference “Pacific-type” margin—but they are also in the eastern Indian Ocean, with relatively short convergent margin segments in the Atlantic Ocean and in the Mediterranean Sea. Globally, there are over 50 major ocean trenches covering an area of 1.9 million km or about 0.5%
Trench coat the trench coat was sized to wear over the British Warm, to offer water protection when the temperature was cold enough to require the heavier coat, which explains the traditionally generous sizing of trench coats; however, makers in recent years have resized trench coats downwards to conform more closely to overcoat sizing, as the two coats, trench and overcoat, would rarely if at all be worn together today. Trench coats have remained fashionable in the decades following World War II. Their original role as part of an army officer's uniform lent the trench coat a businesslike respectability, although many prefer