contrary to popular belief, BBM does not stand for 'BlackBerry Messenger'; it bears a slightly more disturbing meaning. BBM is actually short for 'Big Black Meat', or so some Twitter users seem to think (one example being @BigBlackMeatMan). The abbrevaition is almost always used with the name Darelle, for reasons unknown. One thing is for sure, and it's that this word causes great confusion in the Twitterverse.
By Jennifer Kennedy. The Mariana Trench (also called the Marianas Trench) is the deepest part of the ocean. This trench lies in an area where two of the Earth's plates-the Pacific Plate and the Philippine Plate-come together. The Pacific plate dives under the Philippine plate, which also partially gets pulled along (read more about this collision under oceanic-oceanic convergence here).
Two oceanic plates converging forminga trench between the plates, USGS. Mariana Trench Trenches form in some areas when two oceanic plates converge forming a subduction zone. The Pacific Plate is subducting beneath the Mariana Plate forming Mariana Trench.The Pacific Plate is older and colder than the Mariana Plate.ntroduction. Ocean trenches are natural tectonic plate boundaries between two crustal plates. When a continental plate converges with an oceanic plate a subduction zone forms. The heavier oceanic plate subducts beneath the lighter continental plate forming a trench.