Part one of term paper
A trench is any long, narrow, steep-sided depression in the ocean bottom. The deepest known depression of this kind is the Mariana Trench, which lies east of the Mariana Islands in the western North Pacific Ocean . Of the Earth's 20 major trenches, 17 are found in the Pacific. The only Atlantic trenches are the Puerto Rico Trench north of the ...

Part two of term paper
... of trenches. No abnormalities in the flow of internal Earth heat or variations in the Earth's magnetic field occur at trenches. Precision measurements reveal that the force of gravity generally is lower than normal. Small quantities of brown or red clay, which are signs of organic remains, volcanic ash and lapilli, and coarse, graded layers are found in the trench. Large amounts of remains cannot build up because they either are dragged into the Earth's interior or are distorted into folded masses ...