The Tonga Trench in the South Pacific Ocean is the second deepest trench on Earth, only behind the Mariana Trench in the Pacific Ocean. The Tonga’s deepest point called the Horizon Deep, is at 10,882 metres below sea level. The Tonga Trench is an 850 miles (1,375 km) long channel. Every point of the trench is not 10 km deep. The average depth is 6000 m or 20000 ft.
The Tonga Trench is situated in the southern part of the Pacific Ocean. The trench lies parallel with the eastern shore of Australia. It is can also be joined with islands of New Zealand with a straight line on a map. The Tonga Trench is followed by the Karmadec Trench in the south. These two forms the active Tonga- Karmadec subduction zone.
In the Northern Tonga Trench, the convergence between the Indo-Australian and Pacific plate is going on at a fast rate of 9 inch per year. It is too fast for a geological timescale where we have to consider millions of years?
Active tectonic activity around the Tonga trench results in frequent earth quakes around the area. The island of Tonga experience around 350 quakes per year. Often, the large earth quakes generate tsunamis. The Tonga trench is so deep that the light of sun never reaches to it. As a result, the water inside the deepest parts becomes very cold around 1.1 degree C (34 degrees F). Due to the abysmal depth of the place the water pressure here is extremely high. Due to the high pressure, no light and lack of oxygen, common sea animals cannot survive here. But there are some special fishes and invertebrates that thrive in this ecological niche.
Credit : All Five Oceans
Picture Credit : Google
