Pacific Oceanic Bottom Relief

  • The Pacific Ocean is known as the biggest ocean on the earth which occupies 1/3rd part of the entire globe.
  • Pacific Ocean Extension 16000 km in East-West (Asia Coast to America (West Coast), With this, 14800 km in North or South (Bering Strait – Cape Andre (Antarctica).
  • The average depth of the Pacific Ocean is 4500 m.
  • Both the Pacific Ocean’s coast (E&W) is similar to each other. And they are surrounded by the chains of the folded mountain, descent from coast to the abyssal plain.
  • There are approx. 20,000 islands located in the Pacific Ocean.

Island’s group is divided into 3 categories:-

  1. Continental islands: –
    • Aleutian Islands
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  • Islands of British Columbia of Canada (Vancouver Island, Quadra Island, Denman Island, Gabriola Island, North Pender Island, Salt Spring Island, Hornby Island, Galiano Island, Cortes Island, and Saturna Island).
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  • Chilean islands (Chiloé Island, Robinson Crusoe Island, Alejandro Selkirk Island, Isla Salas y Gómez, Isla Grande de Tierra del Fuego, Navarino Island, Santa Clara Island, San Ambrosio, Mocha Island and Desolación Island).
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  1. Island Archs & Festoons:
    • Kuriles
    • Japanese Archipelago (Shikoku, Kyushu, Honshu, Ishigaki, Yakushima Island, Miyako-Jima, Itsukushima, Kuril Islands, Iriomote-Jima, and Yonaguni).
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  • Philippines (Luzon, Boracay, Mindanao, Siargao Island, Palawan, Negros, Leyte, Mactan, Panay, Samar Island).
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  • Indonesian Islands (Sumatra, Bali, Java, Sulawesi, Lombok, Borneo, Flores, New Guinea, Lesser Sunda Islands and Maluku Islands.

3.     South-West group of islands are categorized into three parts.

  • Melanesia
  • Micronesia
  • Polynesia
Johnson Division of Pacific ocean
Northern Pacific1. It’s the very deepest part of the world.
2. Avg. depth is 5000m-6000m.
3. join with Arctic Sea(Through Bering Straits).
Central Pacific1. A huge no, of islands, are found in this region.
2. volcanic prone region.
South-West Pacific1. Many Islands.
2. Marginal Seas.
3. Extensive Continental.
4. shelvesOceanic Trenches.
South-East Pacific1. Most striking relief- East Pacific ridges
2. Absence of marginal seas.

Continental shelf: continental shelfs are meet in the pacific oceans, those are significantly difference, through an extend and characteristics. It’s found a different place and a unique size, that is divided into two parts such as:

Eastern Coast:

1. Australia and Asia– Coast area are very Broad
– Found the extensive shelves  
2. Width Varies b/w– It’s almost defined as 150-1650 km
3. Depth Ranges– Approx. 1000-2000m
4. Several Islands (Specific Shelves characteristics.– Kuriles
– Japanese islands
– Philippines
– Indonesia
– New Zealand etc.
5. Eastern Marginal Seas– Coral Sea
– Java Sea
– Tasmania
– SeaBering
– SeaArafura
– Sea etc.

West Coast:

  • West coast is less extensive continental shelfs, because its nearby to cordilleran cover chains, which are occupied from folded mountains to specific coastal lands.
  • Its avg. width cover is about 80 km.

East Pacific Rise

EastCharacteristics
1. Ridges1.There are not found mid-oceanic ridges such as the Atlantic or the Indian Ocean.
2. Few Scattered Ridges.
3. East Pacific rise/ridge are albatross plateau.
2 . Wides Cover– 1600 km.
3. Extending size from– North New Zealand to the California Coast.
4. Branches1. Eastern branches- its branch connect with the Chilean coast.
2. Other branches- its rise move toward southward in identified east island rise.
5. Other Ridges1. Galapagos ridges- flow east pacific ridges
i. Branches- Cocos and Carnegic ridges.
2. Hawaii Rise- its increase toward north-west to south-east.
i. Depth- 800-970m.
i. Width- 2650km.
3. New Zealand Ridges- depth 300 to 2000m sea level.
i. Cover near Fiji island plateau.
4. Nazca Ridge- off Peru Coast.

6. Cover Zones
1. Clarion Fracture zone.
2. Challenger fracture zone.
3. Molokai fracture zone etc.
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Basin Of Pacific Ocean

There can divide several kinds of Basin of Pacific Ocean such as:

BasinsCharacteristics
1. Philippine Basin– East area of PhilippineAvg.
– depth: 5000 to 6000m
– Kyushun paian ridge runs in the middle of the basin.
– 5N- south of Japan sea.
2. Fiji Basin– Direction 10s – 32sAvg.
– Depth: 4000m.
– South of Fiji island cover
– Covered: Norkolk island ridge
Karmadec; tonga Trench.
3. Pacific Antarctic Basin– Between the 40s and 60s
– Extends 130w longitude
– South-west of Chilean coast
4. Peru Basin– 5s – 24s longitude
– Avg. depth: 4000m
– Western cover of Peru coast-110w.
5. South Australian Basin– Avg. depth 5000m
– Aka Jeffreys Basin
6. East Australian Basin– Avg. Depth 4500m
– Vary between Australia and New Zealand.
7. South-West Pacific Basin– West karmadec Trench
– 20s – 50s latitude

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