Download Earth and ocean basin

Earth and ocean basin
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Introduction
Distribution of sea and land
The earth’s interior
Ocean and types
Theory of formation of the oceans
The world’s oceans
List of oceanic basins
History and composition of ocean
Relief of sea floor
• Three major components of earth
– Hydrosphere-Ocean
– Lithosphere-Rocks
– Atmosphere-Air
• Biosphere- encompasses part of these three
layers
– Several meters in lithosphere- 6 miles in to
atmosphere-and more than 11,000 meters into
ocean
– World ocean occupy 71% of earth surface
– Average depth of ocean 4 km
The earth basin
• Earth interior-Three distinct layer
• Core
– Inner most portion of earth
– Begins at 2900 km below the surface of earth and
extends up to 3480 km to the center of the earth.
Outer liquid core-> alloy of
• Two cores
Inner solid core  Alloy of Fe & NI  80%
Mantle
• Intermediate layer between earth’s core &
crust
• Accounts for 84% of earth & volume
• It is 2900km thick
• Composed of silicon, magnesium, and iron
• Upper mantle hotter than lower mantle
because it have extensive distribution of radio
active minerals such as uranium, thorium and
potassium
Crust
• Is the uppermost and thinnest segment of
earth
• Thickness various from 5 to 50 km
• It is enriched in basaltic content in oceanic
crust and granitic in continental crust.
• 6 to 50km thick
• Crust is 50km under mountain regions and
less than 5km under ocean
Lower SIMA (silica, magnesium)
• Crust
upper SIAL (silica and aluminium)
Theory of formation of the oceans
• Continental drift theory
• The theory of permanent oceans
World’s Oceans
Ocean
Pacific
Area
millions)
square
kilometers
166,241
Atlantic
(in Volume
(in Depth
of millions) of cubic meters)
kilometers
(in Temperature
Salinity
Remarks
696,184
4,188
3.36
34.62
Coldest, deepest, and
largest ocean, occupying
more than half of the
volume of ocean basins
94,314
337,210
3,736
3.72
34.76
Received large amount
of sediment from many
rivers such as the
Amazon, the Congo, the
Mississippi.
Indian
77,118
284,608
3,872
3.73
34.90
Received large amount
of sediment from the
Indus, the Ganges, and
the Brahmaputra
Total Ocean
362,033
1,349,929
3,729
3.52
34.72
Oceans
occupy
70
percent of the earth’s
surface
Oceanic Basins
Aleutian Basin
Agulhus Basin
Amerasian Basin , Arctic Ocean
Angola Basin
Arabian Basin
Argentine Basin
Bauer Basin
Blake Basin , Atlantic Ocean
Brazil Basin
Canada Basin , Arctic Ocean
Canary Basin
Cape Basin
Central Pacific Basin
Central Polar Basin
Chile Basin
Cocos Basin
Eurasian Basin , Arctic Ocean
Fram Basin , Arctic Ocean
Guatemala Basin
Guiana Basin
Iceland Basin
Labrador Basin
Markarov Basin,Arctic ocean
Madagascar Basin
Melanesian Basin
Mexico Basin
Mid- India Basin
Nansen Basin , Arctic Ocean
Natal Basin
Newfoundland Basin
North Polar Basin
Northwest Pacific Basin
Norwegian Basin
Penrhyn Basin
Perth Basin
Peru Basin
Roggeveen Basin
Sierra Leone Basin
Somali Basin
South East Pacific Basin
South West Pacific Basin
South Fiji Basin
Natal Basin
Newfoundland Basin
North Polar Basin
Northwest Pacific Basin
Norwegian Basin
Penrhyn Basin
Perth Basin
Peru Basin
Natal Basin
Newfoundland Basin
North Polar Basin
Northwest Pacific Basin
Norwegian Basin
Penrhyn Basin
Peru Basin
Roggeveen Basin
Sierra Leone Basin
Somali Basin
South East Pacific Basin
South West Pacific Basin
South Fiji Basin
South Indian Basin
South West Pacific Basin
Tsushima Basin (Ulleung Basin)
West Australian Basin
Peru Basin
Roggeveen Basin
Sierra Leone Basin
Somali Basin
South East Pacific Basin
South West Pacific Basin
South Fiji Basin
South Indian Basin
South West Pacific Basin
Tsushima Basin (Ulleung Basin)
West Australian Basin
Peru Basin
Roggeveen Basin
Sierra Leone Basin
Somali Basin
• Saucer –like depression of the seabed
• have the features of continental margin to
vast structural division of deep ocean
• Largest ocean basin-3-5km
• Stretch from outer margins of continents to
mid ocean ridges
• Cover 71% (36 million sqkm) of earth surface
• Average depth 500 mts
• Five major ocean basin
– Pacific ocean basin
– Indian ocean basin
– Atlantic ocean basin
Pacific Ocean basin
• Eastern side bounded by North and South
American continents
• Northern side bounded by Bering strait
• Western side bounded by Asia, Archipelago
and Australia
• Southern side by southern ocean
– Deepest of all oceans
– Oldest of the existing ocean basin
– The coastal shelf extends to depth of about 180
mts and is narrow along north & south America
Atlantic ocean basin
• The continental shelves of American, African
and European coasts forms the Atlandic ocean
basin
•
The subbasins along American side are
more than 500 mts deep
•
The North American basin, Brazil basin,
Argentina basin are the other sub basins
Indian Ocean basin
• Third largest of five oceans
• Bounded on west by Africa, North by Asia,
East by Australia, South by southern ocean
• The basin includes the
Distribution of land and water in
the earth
• Land and water are unevenly distributed on
the earth
• Continents cover 29.2% of earth surface
• The ocean is directed in to 3 basins called
Atlantic, Pacific and Indian.
• Ocean basin covers 70.8% of earth surface
• The southern hemisphere is dominated by
oceans (80.4%)
• Northern hemisphere contains most of the
lard and is still dominated by ocean (60.7%)
History and composition of ocean
List of oceanic basins
Chemical History of the Ocean
Relief of sea floor
Tabular representation of relief of
seawater
Feature
Width
Relief
Water Depth
Bottom Gradient
Continental Shelf
<300 km
< 20 m
<150 m
<1:1,000(~0.5°)*
Continental slope
<150km
Locally > 2km
Continental rise
<300km
<40km
Drops from
2000+m
1.5-5km
Submarine canyon
1-15km
20-2,000m
20-2,000m
<1:40(3-6°)
Deep-sea trench
30-100km
>2km
5,000-12,000m
---
Abyssal hills
100-100,000m(100km)
1-1,000 m
Variable
---
Seamounts
2-100km
>1,000km
Variable
---
Abyssal plains
1-1,000km
0
>3km
1:1,000-1:10,000(<0.5°)
Midocean ridge
500-1,500km
<1km
>3km
----
Midocean ridge crest
500-1,000km
<2km
2-4km
----
100
+- ~1:40(3-6°)
1: 1,000-1:700(0.5°-1°)