Cycles of the Earth

1
Cycles of the Earth

• Ch 18 Trefil Hazen
• The Sciences

2
All Matter above and beneath the Earths surface
moves in cycles.
3
What drives the earth cycles?

• Sun radiates heat down on the ocean of air and
  water

• Earths hot core or geothermal energy spreads
  upward

4
Demo and describe the water cycle
5
Water cycle constantly transfers the worlds
water between three basic storage reservoirs.

• Oceans contain 97 of Earths water
• Of the 3 of the Earths freshwater
• 2.15 is locked away in glaciers and ice sheets
• 0.62 is groundwater, stored as soil moisture
• 0.009 is in rivers and lakes
• 0.001 is in the atmosphere

6

• Amazingly, the whole shebang of water in lakes
  rivers, water in rain snow, water in our
  bathtub, shower, and drink bottles, amounts to
  only about 1 of the water in the world.

7
(No Transcript)
8
The Water (Hydrologic) Cycle

• p. 442
• Ocean to Atmosphere
• 84 vapor from oceans 16 from continents
• Atmosphere to Surface
• Vapor cools, condenses precipitates out in a
  week, or few hours or few centuries depends.
• 77 precipitation falls on the oceans
• Surface to Ocean
• 23 of precipitation in water cycle meets our
  needs via surface water and ground water.

9
Major steps in the water cycle

• Ocean to Atmosphere
• Atmosphere to Surface
• Surface to Ocean

10
How do the different types of precipitation form?

• Rain--Vapor condenses around aerosols and falls
  from sky.

11
How do the different types of precipitation form?

• Snowice crystals that assemble themselves as
  they fall through a cloud

12
How do the different types of precipitation form?

• Hail--large frozen rain formed in a giant cloud
  of an intense thunderstorm.

13
How do the different types of precipitation form?

• Sleet--falling snow may partially melt and then
  refreeze into a frozen raindrop.

14
Motion of the Ocean
15
Discuss the cause/effect dynamics of global ocean
currents. link
16
Heres a new perspective
17
Explaining ocean motion p. 441

• Great currents move the ocean, distributing heat
  and regulating climate across Earth.
• General scheme
• Warm equatorial water swirls pole-ward and
  circulates in vast ocean areas.
• Cool water moves around the poles and flows
  toward equator as continents allow passage.

18
(No Transcript)
19
(No Transcript)
20
Atmospheric Convection on the Rotating Earth p.
452

• Trade Winds easterlies at equator
• In the tropics, winds prevail from E to W.
• Air warmed new equator travels pole-ward but
  gradually cools and sinks. Earths rotation
  deflects surface winds

21
Atmospheric Convection on the Rotating Earth p.
452

• Polar Easterlies
• In the polar regions, cold dense air sinks and
  moves away from poles.
• Earths rotation deflects surface wind from East
  to West.

22
Atmospheric Convection on the Rotating Earth p.
452

• Westerlies
• Near 30o N S latitude, Earths rotation moves
  air from West to East, as warm air moves to
  poles.

23
Many ongoing processes constantly change Earth.
24
How do rocks cycle ?
25
Rock Cycle
26
Rocks

• Igneous formed by the cooling and
  crystallization of magma (melted rock)
• Sedimentary formed from accumulation of
  weathered material (sediments)
• Metamorphic formed from preexisting rocks that
  have been transformed (changed)

27
Igneous, Sedimentary, Metamorphic

• ü    Each type of rock records a different
  complex past.
• ü    Each type of rock can be changed from one
  form to another and back again.
• ? geologists call these transformations the rock
  cycle

28

• Ch 18 pp. 464-465.
• Try Discussion Questions 1-7,
• And visit links on pacing guide
• Hydrologic cycle
• Atmospheric cycle
• Rock cycle