Introduction to Earth Science Earth Science Chapter 1 Mr. Willis Earth and Space Science WH

 Encompasses all sciences that seek to understand  Earth  Earth’s neighbors in space  Earth Science includes  Geology – literally the “study of Earth”  Physical  Materials composing the Earth  Historical  study of the origin and development of the Earth  Oceanography – a study of the ocean  Meteorology – the study of the atmosphere and the processes that produce weather  Astronomy – the study of the universe Earth Science

 Environment  Surrounds and influences organisms  Physical environment encompasses water, air, soil, and rock  Term “environmental” is usually reserved for those aspects that focus on the relationships between people and the natural environment People and the environment

 Population  Population of the planet is growing rapidly  Rate of mineral and energy usage has climbed more rapidly than the overall growth of population  Current populations  US  314,340,477 (US Census Bureau)  World  7,038,328,935 (US Census Bureau)  World Leader:  China People and the environment

Figure 1.3 in text

Figure 1.2 in text

 Resources  An important focus of the Earth sciences  Includes water, soil, minerals, and energy  Two broad categories  Renewable – can be replenished (examples include plants and energy from water and wind)  Nonrenewable – metals (examples include metals and fuels) People and the environment

Figure 1.6 in text

Figure 1.1B in text

 Environmental problems  Local, regional, and global  Human-induced and accentuated  Urban air pollution  Acid rain  Ozone depletion  Global warming * Natural hazards  Earthquakes  Landslides  Floods  Hurricanes  World population pressures People and the environment

 Science assumes the natural world is  Consistent  Predictable  Not always the case   Goal of science  To discover patterns in nature  To use the knowledge to predict Scientific inquiry

 An idea can become a  Hypothesis (tentative or untested explanation)  Theory (tested and confirmed hypothesis)  Paradigm (a theory that explains a large number of interrelated aspects of the natural world)  Scientific method  Gather facts through observation  Formulate hypotheses and theories Scientific inquiry

 Scientific knowledge is gained through  Following systematic steps  Collecting facts  Developing a hypothesis  Conduct experiments  Re-examine the hypothesis and accept, modify, or reject  Theories that withstand examination  Totally unexpected occurrences Scientific inquiry

 In Earth and Space Science observations are made from smallest objects (atoms) to the largest (stars) Types of scale within Earth and Space Science  Mohs Scale of Hardness  Minerals Hardness  Richter Scale  Earthquakes  Geologic Time Scale  Age of Earth  Fujita Scale  Tornados  HR Diagram  Stars Scaling in Earth Science

Figure 1.6 in text

Figure 1.7 in text

Humans and the Environment Paper Is the recent increase in human fatalities/property damage globally from natural disasters (i.e. hurricanes, floods, tornados, etc.) a function of the global warming/climate change or human population growth/encroachment on areas where man was not intended to habitate. -Using at least four sources, develop a thesis that clearly states your position on the issue and write a 4-5pgs persuasive paper on this topic. -Be sure to include the concepts of the Earth System in your discussion.

 Origin of Earth  Most researchers believe that Earth and the other planets formed at essentially the same time  Nebular hypothesis  Solar system evolved from an enormous rotating cloud called the solar nebula  Nebula was composed mostly of hydrogen and helium Early evolution of Earth

 Origin of Earth  Nebular hypothesis continued  About 5 billion years ago the nebula began to contract  Assumes a flat, disk shape with the protosun (pre-Sun) at the center  Inner planets begin to form from metallic and rocky clumps  Larger outer planets began forming from fragments with a high percentage of ices Early evolution of Earth

The Nebular hypothesis Figure 1.8 in text

 Formation of Earth’s layered structure  As Earth formed, the decay of radioactive elements and heat from high-velocity impacts caused the temperature to increase  Iron and nickel began to melt and sink toward the center  Lighter rocky components floated outward, toward the surface  Gaseous material escaped from Earth’s interior to produce the primitive atmosphere Early evolution of Earth

 Hydrosphere  Ocean – the most prominent feature of the hydrosphere  Nearly 71 percent of Earth’s surface  About 97 percent of Earth’s water  Also includes fresh water found in streams, lakes, and glaciers, as well as that found underground Earth’s “Spheres”

 Atmosphere  Thin, tenuous blanket of air  One half lies below 5.6 kilometers (3.5 miles)  Accounts for all gases in and around the Earth.  Biosphere  Includes all life  Concentrated near the surface in a zone that extends from the ocean floor upward for several kilometers into the atmosphere Earth’s “Spheres”

 Solid Earth  Based on compositional differences, it consists of the  Crust – solid material at the surface  Mantle- 82% of the earth’s volume  Core – Inner (radius ~1216km/754mi) Outer (2260km/1400mi)  Divisions of the outer portion are based on how materials behave  Lithosphere – rigid outer layer (avg. 100km in thickness)  Asthenosphere – weak sphere  Divisions of Earth’s surface – continents and ocean basins Earth’s “Spheres”

Earth’s layered structure Figure1.14 in text

A closer look at the geosphere

Figure 1.16 in text

 Earth is a dynamic body with many separate but highly interacting parts or spheres  Earth system science studies Earth as a system composed of numerous parts, or subsystems  On a macro-scale  Hydrosphere, geosphere, biosphere, and atmosphere  System – any size group of interacting parts that form a complex whole Earth system science

 System  Closed systems are self-contained (e.g., an automobile cooling system)  Open systems – both energy and matter flow into and out of the system (e.g., a river system) Earth system science

 Feedback mechanisms  Negative-feedback mechanisms resist change and stabilize the system  Positive-feedback mechanisms enhance the system  Earth as a system  Consists of a nearly endless array of subsystems (e.g., hydrologic cycle, rock cycle) Earth system science

 Earth as a system  Sources of energy  Sun – drives external processes such as weather, ocean circulation and erosional processes  Earth’s interior – drives internal processes including volcanoes, earthquakes and mountain building  Humans are part of the Earth system  As the dominant species on the planet, our geologic-footprint is also the greatest. Earth system science

End of Chapter 1