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).
The Mariana Trench was created by the process that occurs in a subduction zone, where two massive slabs of oceanic crust collide. At a subduction zone, one piece of oceanic crust is pushed and pulled underneath the other, sinking into the Earth's mantle, the layer under the crust. Where the two pieces of crust intersect, a deep trench forms above the bend in the sinking crust.