Oceanography

Exploring the Ocean Floor Continental Shelf: gradually sloping end of a continent that extends out under the ocean Continental Slope: true edge of a continent; steeper than shelf Abyssal Plain: smooth, nearly flat deep region of the ocean floor Trench: steep canyon in the ocean floor; so deep, cannot see the bottom

Exploring the Ocean Floor Seamount: completely underwater volcanoes Guyot: seamounts with flat, eroded tops Volcanic Islands: underwater volcanic mountains whose peaks break the surface of the ocean Mid-Ocean Ridge: continuous range of mountains with cracks for magma to flow

Ocean Composition The ocean is salty! (31% sodium and 55% chlorine) Oceans are 96.5% water and 3.5% dissolved salts WHY? Rivers and streams deposit minerals into the ocean When water evaporates, the salt is left behind Salinity: the measure of how much salt is in the water

The Dead Sea

Waves Waves: the movement of energy through a body of water

Waves Wind blows across the surface and gives its energy to the water creating waves (the energy is moving, NOT the water) The size of the wave depends on the strength of the wind and on the length of time it blows Can be CONstructive and DEstructive

Waves Wavelength – distance from one crest to the next consecutive crest Wave height – the distance from the crest of a wave to the next consecutive trough Frequency (or period) – the number of waves that pass through a point in a given amount of time

Special Waves Breakers - As the wave moves into increasingly shallow water, the bottom of the wave decreases speed. There comes a point where the top of the wave overtakes it and starts to spill forward — the wave starts to break. Tsunamis – giant waves that form due to volcanoes or earthquakes that occur on the ocean floor

Tides Tides: the daily rise and fall of Earth’s waters on its coastlines caused by the gravitational pull of moon and the Sun the moon’s effect is about twice as much as the Sun’s because it is closer to the Earth Tidal range: difference between high and low tide

Tides The moon pulls on the Earth and the ocean The pull is strongest on the part of the Earth directly facing the moon (A) causing a bulge or a high tide As the ocean (A) and the Earth (B) are pulled, a bulge or high tide is left on the other side of the Earth (C) These bulges (A & C) cause the water level in the places between them (D & E) to decrease. causing low tides Most shores have 4 tides a day, 2 high and 2 low D E

Tides Location of the Sun may impact tides Spring Tides: huge difference in high and low tides; high tides are really high and low tides are really low Neap Tides: small difference in high and low tides; high tides are not that high and low tides are not that low

Currents Currents: large streams of moving water that flow through the oceans Carry water great distances unlike waves https://www.youtube.com/watch?v=Hu_Ga0JYFNg Surface Currents

Currents Surface Currents: currents that occur at or near the surface Caused by winds pushing water across the ocean Follow wind patterns and move in circular patterns Why circular? Currents meet continents and change direction (deflect) Earth is spinning so wind can’t blow straight: Coriolis Effect Greatly affect climate; warm water moves from the equator and cool water moves from polar regions Warm and cool currents warm or cool the air above

Coriolis Effect http://noaacontent.nroc.org/lesson08/l8ex1.htm https://gpb.pbslearningmedia.org/resource/nvcl.sci.earth.coriolis/the-coriolis-effect/

Currents Deep Ocean Currents: currents that carry colder, denser water along the ocean floor from the poles to the equator caused by differences in density Density of water depends on temperature and salinity Move and mix all over Earth

Resources https://www.youtube.com/watch?v=12V3u7bSTlI (Kenya) https://www.ksbw.com/article/windy-weather-causes-upwelling-in-monterey-bay/1397665 (upwelling) https://www.youtube.com/watch?v=r2XN0equt8I (Uganda) https://www.slideshare.net/pramodgpramod/coastal-erosion-mitigation (mitigation)