Tethyan Trench Tethyan Trench The Tethyan Trench was an ancient oceanic trench that existed in the northern part of the Tethys Ocean during the middle Mesozoic to early Cenozoic eras. The Tethyan Trench formed when the Cimmerian Plate was subducting under eastern Laurasia, around 200 million years ago, in the Early Jurassic. The Tethyan Trench extended at its greatest during Late Cretaceous to Paleocene, from what is now Greece to the Western Pacific Ocean. Subduction at the Tethyan Trench probably caused the continents Africa and India to move towards Eurasia, which resulted in the opening of the Indian Ocean. When the Arabian
Middle America Trench east of that in the seaward side. Middle America Trench The Middle America Trench is a major subduction zone, an oceanic trench in the eastern Pacific Ocean off the southwestern coast of Middle America, stretching from central Mexico to Costa Rica. The trench is 1,700 miles (2,750 km) long and is 21,880 feet (6,669 m) at its deepest point. The trench is the boundary between the Rivera, Cocos, and Nazca plates on one side and the North American and Caribbean plates on the other. It is the 18th-deepest trench in the world. Many large earthquakes have occurred in the area