Oceanography Week Five
1. Why is it significant that water is a dipolar molecule?: Hydrogen is electropositive and
oxygen is electronegative creating a charged water molecule with two poles (a dipolar molecule). The electrical
attraction between water molecules pulls molecules closer, making it diflcult to separate the molecules and raising its
boiling point. This attraction is known as hydrogen bonding and creates loosely bonded molecules that are in constant
motion, continually breaking and reforming.
2. Explain how changing the "phase" of water takes or releases heat.: When water is
in a solid phase molecules are forced into a crystalline framework and are less closely spaced. This makes it harder for
water to retain heat. In liquid form the molecules are moving a faster speeds which traps heat.
3. What two things affect the density of ocean water?: Temperature and salinity.
4. Where is the thickest sediment in the ocean basins? Why?: The thickest sediments are
found away from spreading centers (near continental margin or deep ocean) where the seafloor is older and sediments
have had more time to accumulate.
5. What are the four (4) main types of ocean sediment?: Clastic material = rocks and mineral
particles
Hydrogenous (water derived) = sediments
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, Cosmogenic = microtektites and wind seds
Biogenic = from plants and animals (ooze)
6. Where does most of the "dust" come from that is deposited in the oceans?: Dust
storms from arid regions of land such as Africa.
7. What is the CCD and how does it determine what sediment is deposited in the
oceans?: CCD = Calcite Compensation Depth
Below the CCD there is no carbonate ooze because the calcium carbonate dissolves. With increasing depth the water
holds more C02 which results in more carbonic acid. The carbonate acid dissolves the carbonate ooze faster. This means
that the carbonate ooze sediment will be found in shallower water and areas of high productivity.
8. What is a methane hydrate and why are they important?: A methane hydrate consists of
methane enclosed in frozen water molecules. Methane hydrate is a common constituent of the shallow marine ocean
geosphere.
9. Why are most beach sands *mostly* composed of quartz grains?: Quartz grains
are a product of crustal recycling. Quartz grains resist wear and can survive many cycles of erosion, burial, cementation
into sandstone, uplift, and re-erosion.
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1. Why is it significant that water is a dipolar molecule?: Hydrogen is electropositive and
oxygen is electronegative creating a charged water molecule with two poles (a dipolar molecule). The electrical
attraction between water molecules pulls molecules closer, making it diflcult to separate the molecules and raising its
boiling point. This attraction is known as hydrogen bonding and creates loosely bonded molecules that are in constant
motion, continually breaking and reforming.
2. Explain how changing the "phase" of water takes or releases heat.: When water is
in a solid phase molecules are forced into a crystalline framework and are less closely spaced. This makes it harder for
water to retain heat. In liquid form the molecules are moving a faster speeds which traps heat.
3. What two things affect the density of ocean water?: Temperature and salinity.
4. Where is the thickest sediment in the ocean basins? Why?: The thickest sediments are
found away from spreading centers (near continental margin or deep ocean) where the seafloor is older and sediments
have had more time to accumulate.
5. What are the four (4) main types of ocean sediment?: Clastic material = rocks and mineral
particles
Hydrogenous (water derived) = sediments
1/3
, Cosmogenic = microtektites and wind seds
Biogenic = from plants and animals (ooze)
6. Where does most of the "dust" come from that is deposited in the oceans?: Dust
storms from arid regions of land such as Africa.
7. What is the CCD and how does it determine what sediment is deposited in the
oceans?: CCD = Calcite Compensation Depth
Below the CCD there is no carbonate ooze because the calcium carbonate dissolves. With increasing depth the water
holds more C02 which results in more carbonic acid. The carbonate acid dissolves the carbonate ooze faster. This means
that the carbonate ooze sediment will be found in shallower water and areas of high productivity.
8. What is a methane hydrate and why are they important?: A methane hydrate consists of
methane enclosed in frozen water molecules. Methane hydrate is a common constituent of the shallow marine ocean
geosphere.
9. Why are most beach sands *mostly* composed of quartz grains?: Quartz grains
are a product of crustal recycling. Quartz grains resist wear and can survive many cycles of erosion, burial, cementation
into sandstone, uplift, and re-erosion.
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