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