The average starting wage of an apprentice is about 50% of a journey worker's rate of pay. Programs are required to progressively increase the apprentices wages provided the on-the-job training and school performance is satisfactory and in accordance with apprenticeship committee.
The Aleutian Trench formed as the Pacific Plate converged with the North American Plate forcing the Pacific's oceanic plate into the mantle because the Pacific Plate is denser than the North American Plate. The Aleutian Trench and other Trenches formed a subduction zone by converging with other plate tectonics.
Plates include both oceanic crust and continental crust. Stable subduction zones involve the oceanic lithosphere of one plate sliding beneath the continental or oceanic lithosphere of another plate due to the higher density of the oceanic lithosphere. That is, the subducted lithosphere is always oceanic while the over-riding lithosphere may or may not be oceanic.