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Earths Oceans ~ James Gillen, Julia Dunn, Taylor Schellhorn, Brett Ackerman ~ Slide 2 Slide 3 Density Salinity More salt = denser Temperature Higher temperature = lower density Slide 4 Oceans - 71% of the world is made up of oceans Slide 5 Salinity Amount of salt dissolved in a substance Measured in parts per thousand (ppt) Increases in warmer climates because of evaporation Decreases in areas where more fresh water sources enter the ocean Slide 6 Ocean Function Regulates climate (temperature, humidity, etc.) Water Cycle provides rainfall Slide 7 Thanks for Watching! Slide 8 Ocean Floor (Chapter 2, Section 2) By Maddie Nesteruk, Ryan Rosenberger, Gwen Yetter, Nathan Mackouse Slide 9 Studying the ocean floor Sonar So und n avigation a nd r anging Determine oceans depth by sending sound pulses from a ship down into the ocean Satellite Seasat Sends images back to Earth- scientists measure the direction and speed of ocean currents Slide 10 Studying the ocean floor Cont.. Geosat Satellite that measured the changes in the height of oceans surface Used to make detailed maps of the ocean floor Underwater Vessels Piloted Vessels such as Alvin and Deep Flight Alvin has been used for underwater missions Robotic Vessels such as Jason II and Medea Can withstand pressures much greater than those found in the deepest parts of the ocean Jason II is controlled by a pilot at the surface and explores sea floor and Medea is attached to it-explores above the sea floor Slide 11 Continental Margins Slide 12 Active Margins Over a tectonic plate boundary Steep slope Allow trench to form in location Passive margins Not over boundary or near subduction zones Steady decreasing slope Leads directly to abyssal plain Slide 13 The Ocean Floor Slide 14 Margins The Continental Margin contains the Continental Shelf,Slope, and Rise The Deep Sea Basin contains the Abyssal Plain, the Mid Ocean Ridge, Rift valley, trenches, and seamounts Slide 15 Global Winds and Currents ( Chapter 3, Sec. 1) Steph, Sofia, and Jack Slide 16 Global Winds Differences in pressure and uneven heating of Earth contribute to global winds At the poles there is indirect solar energy which creates high pressure so the air sinks and moves towards the equator At the equator there is direct solar energy which creates low pressure causing air to rise Both of these changes create a convection current Slide 17 Direction of Wind Flow Northern hemisphere winds are forced in a clockwise direction Southern hemisphere the winds are forced in a counter-clockwise direction Slide 18 Winds and the Ocean Global winds create surface currents The winds are like blowing on hot chocolate creating ripples Surface currents are affected by global winds, the Coriolis Effect, and continental deflections Global winds do not directly effect deep currents Deep currents are affected by change in density Slide 19 Coriolis Effect The apparent curving of the path of a moving object from an otherwise straight path due to the Earths rotation Cause winds and surface currents to move in curved paths around Earth Slide 20 Deep Currents A stream like movement of ocean water far below the surface Formed by a change in density ( salinity and temperature) Decreasing the temperature of ocean water and increasing salinity increase the waters density Slide 21 Chapter 3 Section 1 Meg and Hannah Slide 22 Surface Zone Warm top layer of the ocean 300 meters below sea level Sunlight heats the layer until 100meters deep Thermocline Second layer of ocean water Extents 300 meters to 700 meters below sea level Temperature drops quickly in this layer Deep Zone Bottom layer the starts at thermocline and extends to the bottom 1 C to 3 C Ocean Temperature Layers Slide 23 Currents Surface currents Controlled by wind! Northern hemisphere Currents flow clockwise Southern hemisphere Currents flow Counterclockwise Slide 24 Waves Deepti Tantry, Gavin Zander, Zoe Williams, Ryan Bullotta Slide 25 Parts of a Wave Slide 26 Approaching the Shoreline As waves get closer to the shore, they lose the depth needed to circulate completely The energy in the wave needs somewhere to go This results in a taller but narrower wave Gravity pulls the high wave crest down, resulting in the wave breaking Slide 27 Surface Waves Wind causes surface currents Slide 28 Tsunamis A giant ocean wave that results from seismic activity Begin under the surface of the water or earth Caused by natural disasters such as earthquakes, volcanic eruptions, landslides Can travel thousands of miles at the speed of a jet plane More of a deeper cause than surface waves