Oceanic trench

The oceanic trenches are the deepest parts of the ocean floor, typically formed when one tectonic plate slides under another. Major world trenches include:

• Aleutian Trench[?]
• Cayman Trench[?]
• Japan Trench[?]
• Kermadec Trench[?]
• Kuril Trench[?]
• Mariana Trench
• Middle America Trench[?]
• Peru-Chile Trench[?]
• Puerto Rico Trench[?]
• Tonga Trench[?]