chp 15.2-15.3 Earth and Space – Oceanography – Flashcards
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Side scan sonar
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technique that directs sound waves to the seafloor at an angle so that the sides of underwater hills and the seafloor can be mapped.
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____ % of earths water is in salt water oceans.
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97
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____% of earths surface is covered by oceans
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71
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Sea Level is effected by
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ice ages, tectonic forces, warm periods.
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3 major oceans
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Pacific, Atlantic, Indian
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Ions
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Dissolved salts, gases, and nutrients present in seawater
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Salinity
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Measure of the amount of dissolved salts in seawater. Effects the density of sea water
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Estuaries
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coastal area of lowest salinity often occurs where the lower end of a freshwater river or stream enters the ocean.
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thermocline
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transitional ocean layer that lies between thesunlit surface layer and the colder, dark dense bottom layer and is characterized by cold temperatures that decrease rapidly with depth. Also known as a transitional layer of the ocean characterized by rapidly decreasing temperatures with depth.
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Antarctic Bottom Water
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The coldest and densest water mass in all the oceans
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Oceanography
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Scientific study of Earths oceans
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Waves
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rhythmic movement that carries energy through space or matter. Generated by wind blowing over the waters surface.
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Crest
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Highest point of the wave
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Trough
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Lowest point of a wave.
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Fetch
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Refers to the area of water that the wind blows across. The longer the wind can blow without being interrupted - (wind duration) over a larger area of water - (fetch), the larger the wave will be.
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Wave height
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Vertical distance between crest and trough. The fetch, wind duration, and wind speed all affect the waves height.
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Wave Length
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Horizontal crest to crest difference.
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Breakers
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Collapsing waves; Affected and influenced by shallow water and by the motion of wave crests, which overrun troughs.
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Upwelling
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Vertical upward movement of nutrient-rich ocean water. Originate in deep waters and primarily found off the western coasts of continents in the trade-wind belts.
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Neap tides
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Occurs during a first-quarter and third-quarter moon. Tides are lowest at this time. Occurs when the Sun, Moon, and earth form a right angle.
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Gyres
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Closed, circular current systems
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Tidal Range
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The difference in height between the levels of high and low tide
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Density currents
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Move slowly in deep ocean waters/caused by differences in temp. and salinity of ocean water in turn affecting its density.
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Gravitation
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Basic cause of tides
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Tides
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Periodic rise and fall of sea level.
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Spring tides
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occur during a full or new moon. The sun earth and moon are all aligned. It causes solar tides to enhance lunar tides causing high tides to be higher than normal and low tides to be lower than normal. Spring and neap tides alternate every two weeks.
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Surface Currents
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Caused by the wind. These currents follow predictable patterns and are driven by earths wind systems. They are wind driven movements of ocean water that primarily affects the upper few hundred meters of the ocean.
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high salinity and cold temperatures cause water to be_____ _____.
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more dense
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Freezing point of sea water is ____. Why?
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-2 degrees C because the salt ions interfere with the crystal structure of ice.
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Evaporation formation
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Removal of salt in which salt is left behind when water evaporates from concentrated solutions of salt water
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Biological Activity
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Removal of salts by organisms that remove calcium ions from water to build shell, bones, and teeth.
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How do volcanoes affect the salt cycle?
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Gases from volcanic eruptions contain water vapor, chloride, and sulfur dioxide. These gases dissolve in water and form chloride and sulfate ions in sea water.
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Salts are added to sea water by
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volcanic eruptions and by the weathering and erosion of rocks.
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Salts are removed from seawater by
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Biological processes, formation of evaporites, wind.
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An example of erosion of rocks are
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ions such as sodium, calcium, iron, and magnesium enter oceans in river run off as the weathering of rocks releases them.
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Order of formation of sea ice
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ice crystals, slush, pancake ice, pack ice
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Volcanism
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The mechanism by which water deep within Earth's interior is brought to the surface
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Polar seas do not have
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Surface layers or thermoclines
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Tidal bulges are always aligned with the ____.
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Moon
