The oceanic trenches are the deepest parts of the ocean floor, typically formed when one tectonic plate slides under another. Major world trenches include:
... device is covered by US patents 3,726,146 (1973) and 5,353,655 (1994) by L.A. Mishler and US patent 5,800,311 (1998) by P.S.Chuang.
External links
www.gyrotwister.de ...