The hydrosphere Flashcards
What is the hydrosphere?
The Earth’s outer layer of water, uniting water in all the different states: solid, liquid and gas
How much water on earth is freshwater?
3%
What is a catchment area?
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 ground water over than region
The watershed/catchment area is determined by what? Which direction does water flow?
- Area determined by natural lines that are formed by the land
- water will flow down slopes/higher ground towards the basin
Give examples of human disturbances on watersheds
- The creation of a reservoir upstream from a hydro-electric power plant, can disturb ecosystems
- Contaminants upstream of the basin can be spread anywhere downstream (loss of habitat up and down)
What plays an essential role in regulating climate? Why? How?
- Oceans
- Because of their ability to absorb heat
- Regulate climate by standardizing the temperature of the Earth
The oceans vary in what?
Temperature and salinity
What factors influence water temperature?
- The seasons (angle of sunlight to Earth as we rotate)
- The latitude (closer to the equator=HOT - lots o fsun all year)
- The depth (deeper=colder) due to less sunlight
Where are the oceans less saline? Why?
The oceans are less saline near the poles of the Earth, where the freshwater ice caps freeze/thaw and thus lower the salt concentration
Where does the hydrosphere obtain its salt from?
It obtains its salt from the weathering (erosion) of the lithosphere (dissolved minerals)
High salinity = ?? density solution
HIGH
What is an ocean current?
It is the movement of seawater in a certain direction
What are the two types of marine currents? Are they interrelated?
They are interrelated
- Surface currents
- Deep currents
Describe surface currents
Mostly generated by WIND the top 400m of ocean water
Describe deep currents (subsurface currents)
- Caused by differences in temperature and salinity and ensure vertical circulation between the different layers of the ocean (800m below the surface)
- Caused by different densities of water (denser sinks and causes circulation)
- cold water (due to ice caps/pack ice/icebergs)=cold +dense thus sinks
- very salty water = denser thus sinks
Describe thermohaline
- combination of surface and deep currents creates ocean circulation acts like a “conveyor belt” of both temperature regulation and salinity distribution
- This process mixes water around the world, thus regulates the Earth’s climate and overall temperature
What is the cryosphere?
The cryosphere is the layer made up of frozen water on Earth
When do ice floes/pack ice form?
What are ice floes/pack ice?
It forms hen 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
How are glaciers formed? Icebergs?
Glaciers are formed by compressing snow on LAND
ICEBERGS: Broken pieces of glaciers that fall into the water are called icebergs.
Do icebergs change the water level when they melt?
No
What are the impacts of melting ice?
- Thermohaline (deep) currents are disturbed by melting pack ice and ice bergs, and glaciers
- There is a rise in sea level, due to the accelerated thawing of glaciers
- less ice= increase global climate change (loosing earth’s cooler)
- Loss of habitat when pack ice melts for animals that move around to hunt
Effects of melting pack ice on climate
when pack ice, less salty than ocean water MELT:
1. Then there is less salt so the water doesn’t sink as much
2. Then this water is less dense than Ocean water so this water does not sink as much.
Thus messing up thermohaline circulation, thus worsening climate change (less redistribution)
3. There is now less surface are to reflect the sun light back away (ALBEDO) and more heat is absorbed by the ocean water
4. Loss of habitat for polar bears and seals
What are the consequences of melting glaciers?
- Reduction of reflectivity, the ALBEDO
- Increase in sea levels
Name the energy resources that use the hydrosphere
- Hydraulic energy
- Marine currents and tides/tidal power plants
Describe hydraulic energy.
Energy from moving water (mechanical energy –> electrical energy)
What are the advantages of hydraulic energy?
- Renewable
- “Cleanish”
What are the disadvantages of hydraulic energy?
- Habitat loss to flood/lack of H2O downstream
- “eh” water quality
- Location dependant
Describe marine currents and tides/tidal power plants (used as energy resources)
Marine currents and tides create large quantities of energy
Tidal power plants use tides to produce electrical energy
Name the advantages of currents/tidal power plants
- Renewable
Name the disadvantages of currents/tidal power plants
- Location dependant
- Accidental sushi (killing fish)
- Ugly beach
What causes tides?
The gravitational pull of the sun and the moon on the waters of the Earth
Does the sun or the moon influence the tides more? Why?
The moon
Because the moon is so much closer to the Earth than the sun, its influence is much greater
How are tidal bulges made?
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 (side facing moon) the gravitational force of the moon pulls the ocean’s waters towards it, creating one bulge. On the far side of the Earth, inertia dominates, creating a second bulge.
