The hydroshpere Flashcards
What is the hydrosphere?
The Earth’s outer layer of water, uniting water in all the different states: liquid, solid, gas (vapour)
Describe catchment areas
An area of land whose lakes and rivers all empty into the same larger body of water. It will catch both above surface water and groundwater over that region.
The watershed area is determined by what? How does water flow?
Determined by natural lines that are formed by the land.
Water will flow down slopes/higher ground towards the basin
Describe human disturbances on watersheds.
Creation of a reservoir upstream from a hydro-electric power plant, can disturb ecosystems
Contaminants upstream of the basin can be spread anywhere downstream
Why does the ocean regulate temperature?
Because of their ability to absorb heat
Oceans vary in temp and salinity
What factors influence water temperature?
- The seasons (angle of sunlight to Earth as it rotates)
- The latitude (closer to equator = HOT)
- The depth (deeper = colder) due to less sunlight
What are ocean currents?
The movement of seawater in a certain direction
What are the different types of marine currents?
- Surface currents
- Deep currents
Why does the ocean regulate temperature? Oceans vary in what?
Because of its ability to absorb heat
Oceans vary in temp and salinity
What factors influence water temperature?
- The seasons (angle of sunlight to Earth as it rotates)
- The latitude (closer to equator = HOT)
- The depth (deeper = colder) due to less sunlight
Where are oceans less saline? Why?
Less saline near the poles of the Earth, where the freshwater ice caps freeze/thaw and thus lower the salt concentration
High salinity = _____ density
High
Describe ice floes/pack ice
Froms when the surface of water freezes due to cold temperatures and breaks off into sheets. This is “slightly” salty ice floating on the ocean, near the poles
Describe surface currents
Mostly generated by wind
Top 400m of ocean water
Describe deep currents
- Caused by differences in temperature and salinity and ensure vertical circulation between different layers of the ocean.
- Heavier water sinks and causes movement/circulation
- Cold water (due to ice caps/pack ice and icebergs) = cold + dense thus sinks
- Very salty water = denser thus sinks
Describe thermohaline circulation
- Combination of surface & deep currents creates ocean circulation of both temperature regulation and salinity distribution
- This process mixes water around the world, thus regulates the Earth’s climate and overall temperature
Effects of melting pack ice on climate
When pack ice (less salty than ocean water) melts:
- Less salt in the water so it doesn’t sink as much
- Water is less dense than Ocean water so this does not think as much, messing up thermohaline circulation, worsening climate change
- Less surface area to reflect sunlight back away (albedo). More heat absorbed by the ocean water
- Loss of habitat for polar bears and seals
Describe ice floes/pack ice
Froms when the surface of water freezes due to cold temperatures and breaks off into sheets. This is “slightly” salty ice floating on the ocean, near the poles
Describe glaciers
Formed by compressing snow on land
Describe icebergs
Broken pieces of glaciers that fall into the water are called icebergs
Describe the impacts of melting ice
- Thermohaline currents are disturbed by melting pack ice & icebergs and glaciers
- There is rise in sea level due to accelerated thawing of glaciers
- Less ice = more global climate change
- Loss of habitat when pack ice melt for animals that move around to hunt
- Decrease of albedo
Consequences of melting glaciers
- Reduction of reflectivity (ALBEDO)
- Increase in sea levels
Describe how tides work
- Caused by gravitational pull of the sun and moon on the waters of the Earth
- Because the moon is so much closer to the Earth than the sun, its influence is much greater
- Gravity and inertia act in opposition on the Earth’s oceans, creating tidal bulges on opposite sides of the planet. On the “near” side of the Earth (the side facing the moon), the gravitational force of the moon pulls the ocean’s waters toward it, creating one bulge. On the far side of the Earth, inertia dominates, creating a second bulge.
