Earth Systems and Cycles Earth Systems and Cycles

Earth Systems and Cycles

Earth Systems and Cycles n Approaches to studying earth science: – Reductionist – Holistic

Earth Systems and Cycles n Reductionist Approach – Divide earth into separate units Atmosphere n Hydrosphere n Biosphere n Lithosphere n

Earth Systems and Cycles n Holistic Approach – Earth is studied as a unified system with interacting components

Earth Systems and Cycles n System - any portion of the universe that can be isolated from the rest of the universe for the purpose of observing changes

Systems Analysis

Earth Systems and Cycles n System – A system is any portion of the universe. . . Is whatever the observer defines it to be n A conceptual model n Limits are set for the convenience of our study n

Earth Systems and Cycles n System – A system … is isolated from the rest of the universe for the purpose of observing changes n We must set boundaries around our system to separate it from its surroundings

Earth Systems and Cycles n System – Types of Systems n Isolated - system in which boundaries prevent the system from exchanging either matter or energy

Earth Systems and Cycles n System – Types of Systems n Closed - system in which boundaries permit the exchange of energy, but not matter, with its surroundings

Earth Systems and Cycles n System – Types of Systems n Open - system in which boundaries permit the exchange of both matter and energy across its boundaries

Open, Isolated, and Closed Systems

The Earth System

Earth Systems and Cycles n The Earth System – Subsystems are huge reservoirs in which material and energy are stored before moving on

Earth Systems and Cycles n The Earth System – Earth System Science - the study of the earth and relationships among its subsystems

Earth Systems and Cycles n The Earth System – Constant cycling of matter and energy among subsystems

Earth Systems and Cycles n Earth Cycles – Energy Cycle – Hydrologic Cycle – Biogeochemical Cycles – Rock Cycle

Earth Systems and Cycles n Earth Cycles – Energy Cycle n Internal and external energy sources that drive all the major Earth cycles

Earth Systems and Cycles n Earth Cycles – Energy Cycle n Energy inputs – Solar radiation – Geothermal energy – Tidal energy

Earth Systems and Cycles n Earth Cycles – Energy Cycle n Energy outputs – Reflection – Re-radiation

Earth Systems and Cycles n Earth Cycles – Hydrologic Cycle n n Movement of water among Earth’s subsystems Driving energy source is solar radiation

The Hydrologic Cycle

Earth Systems and Cycles n Earth Cycles – Biogeochemical Cycles n n Movement of various chemicals among Earth’s subsystems Examples – Carbon – Nitrogen – Oxygen

Earth Systems and Cycles n Earth Cycles – Rock Cycle n Reflects interactions between internal and external processes – Internal processes driven by geothermal energy (radioactive decay) – External processes driven by solar radiation

The Rock Cycle