1 Earth’s Many Cycles 10 November 2015 Chapter 18 Presented by Dr. Geller Great Idea: All matter above and beneath Earth’s surface moves in cycles.

2 Chapter Outline Cycles Small and Large The Hydrologic Cycle The Atmospheric Cycle The Rock Cycle

3 Cycles Small and Large

4 Recycling Where did the aluminum can go? Atoms last virtually forever –Different forms Lava flow bonded to oxygen Solid rock Soil Aluminum metal Recycling saves energy

5 The Nature of Earth’s Cycle Earth materials move in cycles A change in one cycle affects the others Atoms constantly moving and recycling –Reservoirs –Hydrologic cycle –Atmospheric cycle –Rock cycle Heat –Hot  cold –Sources Sun Geothermal processes

6 The Hydrologic Cycle

7 Reservoirs of Water Amount of water on earth is fixed Major repositories –Ice caps –Glaciers Unseen reservoirs –Groundwater aquifers

8 Movements of Water Between Reservoirs Hydrologic cycle –Short-term transfer of water between ocean and land

9 The path of groundwater

10 Ocean Currents Redistribute heat across planet

11 Chemical Cycles in the Oceans Chemicals in constant motion Saltiness –Constant over several hundred million years –Primarily determined by Na + and Cl - ions –Residence time Chemical cycle

12 Ice Ages Ice Age –Water locked in glaciers –Glaciers advance from poles Current ice age –Interglacial period Earth’s total water is fixed –Ice caps, glaciers grow –Sea level drops

13 Milankovitch Cycles Milankovitch –Serbian civil engineer –Relationship between earth and sun are affected by variations in earth’s rotation and orbit Precession Change in angle of axis of rotation

14 The Atmospheric Cycle

15 Atmosphere Composition –Nitrogen (78%), Oxygen (21%), Argon, Water Vapor, CO 2, Methane, other Atmospheric Pressure –pressure exerted by atmosphere Warming –Sun - solar constant is not really constant –greenhouse effect warming due to the transparency of a substance to radiation at visible wavelengths and opacity to infrared radiation

16 The Greenhouse Effect Solar energy is the energy source for the atmosphere In the greenhouse effect, some of this energy is trapped by infrared absorbing gases in the atmosphere, raising the Earth’s surface temperature above what it would be if there was no greenhouse effect

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20 Industrial chemicals released into the atmosphere have damaged the ozone layer in the stratosphere

21 The Earth’s atmosphere has changed substantially over time The Earth’s atmosphere differs from those of the other terrestrial planets in its chemical composition, circulation pattern, and temperature profile The Earth’s atmosphere changed from being mostly water vapor to being rich in carbon dioxide A strong greenhouse effect kept the Earth warm enough for water to remain liquid and to permit the evolution of life

22 Structure of the Atmosphere

23 Air Masses: Reservoirs of the Atmosphere Air mass –Uniform temperature and moisture Weather –State of the atmosphere Climate –Long-term average of weather

24 Weather Five variables define state of atmosphere –Temperature Ground level –Air pressure Decreases with altitude Jet stream –Humidity Atmospheric water content –Cloudiness Concentration of water droplets –Prevailing winds Consequence of atmospheric convection

25 The General Circulation of the Atmosphere Circulation powered by Sun –Air heated and rises –Cools and sinks Prevailing winds –Caused by earth’s rotation

26 Common Storms and Weather Patterns Severe weather –Tropical storms Hurricanes typhoons –Tornadoes Weather cycle –El Nino

27 Climate Little change over short periods Influences on climate –Large bodies of water –Ocean currents –Mountain ranges Earth’s climate –Movement of tectonic plates

28 Understanding Climate Long-term climate –Oceans –Mountains –Sunlight Amount radiated back to space Prediction –Global circulation models

29 The Rock Cycle

30 Rock Cycle Overview

31 Igneous Rocks –Solidify from hot liquid Types –Extrusive Solidify at surface –Intrusive Solidify below surface

32 Sedimentary Rocks Sedimentary rock –From grains of weathered rock Formation –Compaction –Cementation Examples –Sandstone –Shale –Limestone

33 Metamorphic Rocks Metamorphic rock –Pressure and heat Not enough heat to melt Examples –Slate –Schists –Gneisses –Quartzite

34 The Story of Marble Marble –Metamorphic rock Process of formation –Begin as limestone –Subjected to heat and pressure –Erosion exposes rocks

35 Surface Building Processes Faulting –formation of a crack caused by relative movement of rock on either side of a fracture different types - normal, reverse, thrust

36 Mountains “elevated parts of the Earth’s crust that rise abruptly above the surrounding surface” Causes –folding, faulting, volcanic activity

37 Folds –bends in layered bedrock Anticline/\ Syncline \/

38 Volcanoes “hill or mountain formed by the extrusion of lava or rock fragments from magma below” Different types –shield, cinder cone, composite (composite shown)

39 Earthquakes Defined as “quaking, shaking, vibrating, or upheaval of the ground” Earthquake causes –elastic rebound theory Intensity measure –Richter Magnitude not linear scale