OCNG 251 Exam 2 Study Guide Summary of Emails 1 Scientists Discover Thousands Of Uncharted Mountains Hidden Beneath The Sea new topographic map of the earth discovers volcanos or seamounts altimetry measures sea surface height from space by timing how long it takes a radar signal to reflect off the ocean and return suggests the volcanoes did not erupt above a mantle plume a blob of hot rock that rises from the deep mantle the layer under the crust 2 35 000 walruses are swarming Alaska s shore because their sea ice is vanishing scientists observed one of the biggest land haul outs in recent memory in northern Alaska with an estimated 35 000 walruses crowding the shore of a remote barrier island near Pt Lay 3 Ditch U N temperature target for global warming study says world s environment ministers agreed in 2010 to cap a rise in average surface temperatures at 2 degrees Celsius OSLO Reuters believe the goal should be ditched effectively unachievable 4 Unexpected meteorite crash in Nicaragua highlights necessity of space program to protect from imminent danger a meteorite crashed in Nicaragua s capital Managua on September 7 the government reported raising new concerns that human civilization remains unprepared for the potential of catastrophic space impacts 5 Strange Looking Sea Creature Discovered on Ocean Floor scientist found a strange sea creature that resembles some kind of siphonophore that only live in the deep ocean Ch 5 Water and seawater I Atoms isotopes and molecules A Atoms basic building blocks of matter can be represented in spheres in various sizes Atomic number is the number of protons in the nucleus Atomic mass is the number of protons and neutrons in the nucleus B Isotopes Atoms with the same atomic number but different number of neutrons therefore a different atomic mass C Molecules a group of two or more atoms held together by mutually shared electrons smallest form of a substance II Hydrogen has 1 electron Oxygen has 8 electrons Covalent ionic and Gary US bonds A Covalent due to the sharing of hydrogen and oxygen atom o a lot of energy to break them B Ionic produced by an electrostatic attraction between oppositely charged ions C Hydrogen weak attraction between a partially positive Hydrogen and a partially negative Oxygen or Nitrogen o weaker than covalent bonds III Structure of the polar water molecule the hydrogen bond A Polarity o Water is polar because the single electron from each of the two hydrogen atoms being shared with the larger oxygen atom covalent bonds spend more time near the oxygen causing it to be slightly negative and the hydrogen atom to be slightly positive IV The anomalous properties of water High latent heat capacity weather modification High freezing and boiling temperatures liquid water at Earth s surface Expansion upon freezing weathering of rocks High surface tension capillarity High dielectric constant dissolving power Changes of state in water latent heats of melting and vaporization A Latent heat of melting The heat energy that must be added to 1 g of a substance at its melting point to convert it to a liquid B Latent heat of vaporization The heat energy that must be added to 1 g of a substance at its melting point to convert it to a liquid V VI Heat capacity of land vs water impacts on climate A Heat Capacity The heat capacity of a substance measures the amount of heat required to raise the temperature of 1 gram of that substance by 1 C The heat capacity of a substance measures the amount of heat required to raise the temperature of 1 gram of that substance by 1 C Because of water s high heat capacity oceans have moderate climates while land continental areas experience much larger changes VII Solutions and dissolving power of water A Solution A state in which a solute is homogeneously dissolved in a liquid solvent Water is the solvent for the solution that is ocean water Salts are the solutes in ocean water VIII Salts in seawater definition and measurement of salinity A Salinity Amount of dissolved solids in seawater B Ocean Water 96 53 water 3 47 or 34 7 dissolved solids Chlorine sodium sulfur magnesium calcium and potassium make up 99 of dissolved solids in ocean water C Units Parts per thousand g kg or grams of a substance per kilogram 1000 g of ocean water Parts per million mg kg milligrams of a substance per kilogram 1000 g of ocean water D Measurement taste optical refractometer titration for Cl ion electrical conductivity IX Density of pure water and seawater dependence on T S A Pure Water maximum density of 1 000 g cm3 at 4 C density increases as the temperature decreases B Seawater saltier the water the denser it becomes and lowers the freezing point to below 0 degrees At T 20 C S 35 ppt seawater density 1 0247 Latitude and depth determine the temperature and affect the salinity X Typical T S and density structures in the ocean A Pynocline Zone in which density increases with increasing depth From 0 1 000 meters Increasing density farther down as temperature gets colder B Halocline Zone of rapid salinity increase or decrease with depth Often coincides with thermocline C Thermocline Temperature changes rapidly with depth XI Both thermocline and halocline contribute to form pycnocline since temperature and salinity affect density Acidity buffering and pH A Acidity a compound that releases hydrogen atoms when dissolved in water rainwater is acid B Buffering protects the ocean from getting too acidic or too basic ocean has a large buffering capacity C pH measure of the hydrogen ion concentration rain water about 6 seawater about 8 pure water 7 Ch 6 Air Sea Interaction I Energy from the Sun Solar energy heats the surface of the earth creates atmospherics winds therefore they drive most of the surface currents and waves in the ocean radiant energy is responsible for motion in the atmosphere and the ocean II Seasons and the Earth s orbit A Seasons The spin axis is tilted 23 5 to the plane of the Earth s orbit causing solar radiation to vary in angle as the Earth revolves around the Sun B Earth s orbit Plane of Elliptic Surface connecting all points on Earth s orbit III The global heat budget and redistribution of heat A Global heat budget describes all the ways in which heat is added to and subtracted from earth important variations with latitude balanced overall gozinter gozouter B Redistribution of heat Heat is gained in equatorial and sub tropical regions Heat is lost in Arctic and Antarctic regions tropics don t get