1. 2.1 Exploring the Ocean

2. The water in Earth’s oceans varies in salinity, temperature, and depth The water in Earth’s oceans varies in salinity, temperature, and depth The ocean is made up of salt water NOT fresh water The ocean is made up of salt water NOT fresh water The ocean is made up of 96.5% water and only 3.5% salt. The ocean is made up of 96.5% water and only 3.5% salt. salinity – the total amount of dissolved salts in a sample of water salinity – the total amount of dissolved salts in a sample of water Sodium chloride (table salt) makes up most of the salt in ocean & sea water (85.6%) Sodium chloride (table salt) makes up most of the salt in ocean & sea water (85.6%) –chloride = 55% – sodium = 30.6% There is less salinity near the surface of the ocean due to the fresh water from precipitation There is less salinity near the surface of the ocean due to the fresh water from precipitation

3. There can be more salinity on a hot day due to evaporation – salt is left behind when the water evaporates There can be more salinity on a hot day due to evaporation – salt is left behind when the water evaporates There can also be more salinity near the poles. Water freezes leaving the salt behind There can also be more salinity near the poles. Water freezes leaving the salt behind Salt acts like an anti-freeze by interfering with the formation of ice – meaning the more salt the water has, the colder it has to be in order to freeze Salt acts like an anti-freeze by interfering with the formation of ice – meaning the more salt the water has, the colder it has to be in order to freeze Which has a higher density – salt water or fresh water? Which has a higher density – salt water or fresh water? Salt water has a higher density than fresh water Salt water has a higher density than fresh water

4. Temperatures at the surface of the ocean vary with location and the season Temperatures at the surface of the ocean vary with location and the season Water near the equator is about room temperature Water near the equator is about room temperature As you travel away from the equator (in either directions) the water gets cooler As you travel away from the equator (in either directions) the water gets cooler Why is this? Why is this? Direct sunlight VS indirect sunlight Direct sunlight VS indirect sunlight Direct sunlight is stronger and warmer than indirect sunlight Direct sunlight is stronger and warmer than indirect sunlight

5. As you descend through the ocean, the water temperature decreases. As you descend through the ocean, the water temperature decreases. Why? Why? Further away from the sun’s radiation. Further away from the sun’s radiation.

6. water column – a vertical section of the ocean that lowers in temperature the deeper one goes water column – a vertical section of the ocean that lowers in temperature the deeper one goes 3 zones in the ocean’s water column: 3 zones in the ocean’s water column: 1.surface zone – smallest zone, near the surface, warmest zone, affected most by sun and weather 2.transition zone – in the middle of surface and deep, has the greatest and most rapid change in temperature 3.deep zone – biggest zone, bottom of the ocean, coldest zone

7. As you descend through the ocean, the water pressure increases. As you descend through the ocean, the water pressure increases. A scuba diver can only descend 40 meters due to the immense pressure A scuba diver can only descend 40 meters due to the immense pressure After 40 meters a submersible is needed (an underwater vehicle built of material to resist pressure) After 40 meters a submersible is needed (an underwater vehicle built of material to resist pressure)

8. On average the ocean floor is more than twice as deep as the Grand Canyon (a little less than 2 ½ miles deep). On average the ocean floor is more than twice as deep as the Grand Canyon (a little less than 2 ½ miles deep). The bottom of the ocean floor is very dark, cold, and has extreme pressure. The bottom of the ocean floor is very dark, cold, and has extreme pressure. sonar – SOund NAvigation Ranging – uses sound waves to calculate the distance to an object sonar – SOund NAvigation Ranging – uses sound waves to calculate the distance to an object sonar was used to map the bottom of the ocean floor sonar was used to map the bottom of the ocean floor The biggest mountains in the world are underwater The biggest mountains in the world are underwater

9. There are 6 ocean floor features that are created due to plate movement: There are 6 ocean floor features that are created due to plate movement: trench – a long, deep valley on the ocean floor where old ocean crust sinks back toward the mantle (example: Marianas Trench) trench – a long, deep valley on the ocean floor where old ocean crust sinks back toward the mantle (example: Marianas Trench) mid-ocean ridges – long chains of underwater mountains on the ocean floors – lava erupts through them and forms new ocean crust mid-ocean ridges – long chains of underwater mountains on the ocean floors – lava erupts through them and forms new ocean crust seamount – a volcanic mountain rising from the ocean floor that doesn’t reach the surface seamount – a volcanic mountain rising from the ocean floor that doesn’t reach the surface What is its name once it reaches the surface? What is its name once it reaches the surface? Island Island

10. continental slope – the steep edge of the continental shelf continental slope – the steep edge of the continental shelf continental shelf– a shallow area that extends outward from the edge of each contient continental shelf– a shallow area that extends outward from the edge of each contient abyssal plain – a smooth, nearly flat region of the ocean covered with thick layers of mud and silt abyssal plain – a smooth, nearly flat region of the ocean covered with thick layers of mud and silt