Topic 4 Unit 5 SCIENCE Flashcards
what percentage of the Earth’s surface do oceans cover?
70%
Name 3 ways the oceans affect our daily lives.
- Food
- Transportation
- Weather
- Water cycle
- Recreation
The amount of salt dissolved in a liquid is called ______
Salinity
Where do the salts in the ocean come from?
- Start out as rocks
- Rivers and groundwater flow OVER the rocks to pick up salts and carry them to the ocean
FRESH WATER CONTAINS MANY OF THE SAME SUBSTANCES AS SEAWATER
Plate Techtonics
The movement of continental and oceanic plates
Continental shelf
Flat edge of land that jets out into the ocean
Continental slope
out from the shelf, land plunges at a steep level to the sea floor
Abyssal Plain
wide open area - deepest part of the sea floor
What feature develops where the edges of an ocean plate pushes against the edge of a continental plate?
Trenches
What are trenches?
Steep sides canyons
- Can result when plate is forced under
ex/ mariana’s trench
Where do waves begin and what starts moving them?
Ocean waves are large ripples, set in motion by steady winds. Begin out at OPEN SEA - started by the WIND
How high can waves get from a hurricane wind?
Up to 30m high
How do you measure wavelength and wave height?
Wave length - Distance from crest to crest or trough to trough
Wave height - From the trough to the crest
How are some of the worlds highest waves produced?
Earthquakes, volcanic eruptions, disturbance in sea floor, tsunamis, landslides.
Define swell
Steady movements of smooth waves near the shore. They are caused by winds and storms far out at sea
Explain how a wave acts as it reaches the shore.
- Trough SLOWS because of FRICTION as it bottoms to the sea floor
- Crest still moves quickly
- Crest topples over the trough and BREAKS on shore
When do spring tides occur?
Largest tidal movement and occurs when the Earth, moon, and sun are in a line.
When do neap tides occur?
Smallest tidal movements and occur when the sun and moon are at right angles to each other.
*TIDES ARE RELATED TO THE GRAVITATIONAL PULL OF OUR MOON
Tidal range
Difference between a high and a low tide
Ocean currents are like a massive _____ within the ocean
River
Name the 3 factors that affect the direction of winds and surface currents.
- Uneven heating of the atmosphere
- Rotation of Earth
- The continents/land - deflects wind
In which direction do surface currents flow in the Southern hemisphere?
Currents turn counter clockwise
In which direction do surface currents flow in the Northern hemisphere?
Currents turn clockwise
