My self Dr. P.K Anthwal . This is my best PPT title important trenches of the world.

1. Oceanography
Important Tranches of the
world
BY
DR. P.K Anthwal

2. What is Trenches??????
• Oceanic trenches are topographic depressions of the sea floor, relatively narrow in
width, but very deep.
• These are the oceanographic features of the deepest part of oceanic floor( Hedal
zone)
• They are convergent plate boundaries, along which lithospheric plates move
towards each other at rates that vary from a few millimeters to over ten
centimeters per year.
• Trench are formed in both cases either ,where convergence of oceanic-continental
plates or oceanic-oceanic plates, but normally also they found when oceanic-
oceanic plate sub ducting into each other.

3. • Trenches are generally parallel to a volcanic island arc, and about 200 km(120mi) from a
volcanic arc. Oceanic trenches typically extend 3 to 4km (1.9 to 2.5 mi) below the level
of the surrounding ocean floor.
• The greatest ocean depth measured is in the Challenger deep of the Mariana trench at a
depth of 11,034 m (36,201) feet below sea level.

5. Trenches of pacific ocean
Sanandreas trench

7. Facts
• Ocean trenches are long, narrow depressions on the seafloor.
• These trenches are the deepest parts of the ocean - and some of the deepest
natural spots on Earth.
• Ocean trenches are found in every ocean basin on the planet, although the
deepest ocean trenches are found in the Pacific as part of the so-called “Ring of
Fire” that also includes active volcanoes and earthquake zones.

8. Important Points
• Tonga trench is located in the south-west Pacific Ocean and at the Kermadec
Tonga Subduction Zone’s northern end, the Tonga Trench lies around 10.882 km
below sea level.
• Mariana trench is located in the western Pacific Ocean, the Marina Trench is
considered to be the deepest part of the Earth’s surface. In fact, it is the
Challenger Deep in the Mariana Trench that is known as the deepest point.
• Kurile - Kamchatka Trench is another deepest part of the ocean belonging to the
Pacific Ocean, this trench lies at a considerable depth of 10.5 km below sea level.

9. • Java Trench, also called Sunda Double Trench, deep submarine
depression in the eastern Indian ocean that extends some 2,000 miles
(3,200 km) in a northwest-southeast arc along the southwestern and
southern Indonesian archipelago.
• The South Sandwich Trench is a deep arcuate trench in the South
Atlantic Ocean lying 100 kilometers (62 mi) to the east of the South
Sandwich Islands. It is the deepest trench of the Southern Atlantic
Ocean, and the second deepest of the Atlantic Ocean after the Puerto
Rico Trench.

10. It’s the Time of Quiz?
• Trenches are formed under………….plate boundary.
• Trenches are generally parallel to a ……….., and about……..km from a volcanic
arc.
• Oceanic trenches typically extend……….. below the level of the surrounding
ocean floor.
• The greatest ocean depth measured is in the……….. of the……..trench at a depth
of 11,034 m (36,201) feet below sea level.
• Ocean trenches are ………, ………….. depressions on the seafloor.
• Puerto Rico trench located at……………..
• South sand which trench located at…….

11. • Tonga trench are located at…………….ocean.
• Java & Sunda trench are located at……..ocean.
• Mariana trench lies at..
1. North Atlantic
2. South pacific
3. North pacific
4. South Atlantic
• Which of the following trenches is/are not located in the pacific ocean?
 Tonga trenches
Mariana trenches
Java trench
South sandwich Trench
Kurile- Kamchatka trench