Oceanography-100 SDSU Exam 2 Questions and Answers Graded A 2024

The Water molecule and basic atomic structure? - 2 positive end hydrogen and one negative end oxygen what makes up the water molecule, the charges, the bond angle? - H end- positive charge O end- negative charge looks like a mickey mouse head What's so peculiar about this molecule? - The fact that is has hydrogen bonds which are independent of the covalent bonds as well as it being a polar molcule H- The kinds of bonds in the water molecule? The kinds of bonds connecting all the water molecules together to form liquid? - In the water molecule there are covalent bonds, but in order for water molecules to be connected together they have hydrogen bonds What do these bonds lead to? (important features of water...) - These bonds lead to the intermolecular bonds that allows cohesion to be create surface tension Polarity - why is water a polar molecule? What do we call water as a result and why? - Water is a polar molecule because it had a positive end and a negative end and because of this we call it the universal solvent What happens to salt (NaCl) in water? - It will dissolve What are the 3 phases of water and how does one get changed to another? - Ice- Molecules are locked into place (all molecules connected by hydrogen bonds) Water- most molecules connected (most connected by hydrogen bonds) Vapor- independent molecules () what is the heat capacity of water? - very high because oceans absorb and release huge amounts of heat with little change in temperature What is the heat capacity of sand? - lower heat capacity because it takes less heat to raise it's temperature How does Salinity and Temp affect Density? - Temperature decreases - Density increases Salinity increases - Density increases (because there is more mass) What is the ocean's influence on coastal climates? - oceans moderate the temperature along the coasts making it much cooler than inland What is density? - mass/volume What happens to warm brackish water - thermal expansion? - thermal expansion becomes less dense What's the temp of the max density of water? - 4*C (1g/cm3) What happens at the equator? - The sun warms the Earth, which transfers heat to the air above, causing it to rise. This creates a low pressure belt with rising air, clouds and rain. Why exactly does ice float on water? - ice is less dense How does the density of water change with freezing? - it becomes less dense What happens to cold, salty water - thermal contraction? - It's denser from the salt and it also contracts because it's cold so it's even denser Salinity - Total amount of dissolved solids (ions) in water h Application: the salinity of the Mediterranean, the history of the Mediterranean basin... salinity of the Baltic Sea... - the mediterranean sea dried up 6 mill. years ago and we know this because there are layers of solid rock salt found underneath the layers of sediment and it dried up because techtonics closed the ocean basin; the latitude is around 30* and the salinity overall is higher than 35 per mil. Polar Latitudes - low salinity, high precipitation, low evaporation, river run off, melting icebergs Subtropical Latitudes (30*) - high salinity, high evaporation, low precipitation, low runoff Equator - salinity in beween, high evaporation and precipitaiton what are the evaporation latitudes and the precipitation latitudes? - precipitation at its peak at the equator What are the most abundant salt ions? - chloride and soduim WRivers hat is average salinity in the world's oceans? - 35% What are the most abundant sources of salts? - continental erosion, volcanoes, etc... - brought to the ocean primarily by primarily by rivers because of continental erosion; Volcanic activity and Hydrothermal vents Density structure of the surface layer? - 2%; goes down to ~200m; mixed warm layer - driven by weather/sunshine/wind Density structure of the thermocline? - 18%; 200m-1000m; rapid temp decrease with depth to about 40