|theImage.com     Notes on Basic Geology|
|Notes created & information organization based on the book:
"The Dynamic Earth - an introduction to physical geology"
Brian Skinner & Stephen C. Porter   (further book information here)
also look at www.wiley.com for additional resource information
|Oceans & Margins - Page 1|
|Factoids||~ 70 - 71% of the earths "current surface"|
Average Depth: 3.8 km
Volume: 1.35 billion cubic km (1/2 in Pacific)
356,632,265,407 gallons or 1,426,529,076,704 qts or .... 2,853,058,153,408 big-gulps!
trillion - billion - million - and a little change
1.) Atlantic Ocean
2.) Pacific Ocean (11,035 m Mariannas Trench)
3.) Indian Ocean
4.) Southern Ocean
|Chemically||sodium chloride (75%) - sulfate, magnesium, calcium, potassium, bicarbonate, bromine make up most of the rest|
|33 - 37 parts per thousand (salts)|
|The land erosion carries about 2.5 billion tons of material into the sea yearly. Other materials are gases from volcanic eruptions (CO2, SO2, H2O, Cl) which also deposit in the ocean. Dust from the deserts blow into the oceans, and finally man creates an interesting soup that he dumps into the oceans.|
|So the $64,000 dollar question?||
If this has been happening for billions of years, why aren't the seas full of salt, or at least at a much higher concentration of salts?
There are many processes at work in the ocean that also remove salts or dilute salt from the ocean ...
1.) Sea life - calcium - phosphate (shells)
4.) addition of river water (fresh-almost)
For now the rate of extraction is the same as the rate of input, and thus the oceans enjoy a roughly constant salinity.
|Salinity is not constant throughout the oceans||
In latitudes where there are deserts or continuous heat there is more evaporation of the ocean and salinity rises. At the equator salinity drops because there is frequent rain, and it drops nearer the poles as there is increased precipitation and ice.
Enclosed bodies of water surrounded by land (especially arid land) have the highest salinity, like: the Red Sea, and the Mediterranean Ocean.
Record land temperatures (58° C = 134° F) --- (-88° C = -126° F) .....
Record ocean temperatures (36° C = 97° F ) (-2° C = 28° F) .....
The ocean has a high heat capacity ... that means it can absorb or lose a large amount of heat without a major change in its overall temperature.
People who live along sea coasts get the benefit of milder changes in temperature between the seasons. Due to this greater heat capacity.