Chapter 1 Introduction to Earth Science

What is Earth Science? 1.1 What forces produced the mountains shown on page 1? Why does our daily weather change? Is our climate changing? How old is Earth? How is Earth related to other planets in the solar system? What causes ocean tides? What was the Ice Age like? Will there be another?

Overview of Earth Science 1.1 Deals with Earth and its neighbors in space Geology “study of Earth” 2 broad areas Physical – examination of materials that make up Earth & explain possible process that shape our planet Earthquakes, mountains, volcanoes, erosion, rocks, minerals Historical – understand Earth’s long history est. time line

Overview of Earth Science Continued… 1.1 Oceanography – study coastal process, seafloor topography, marine life, and composition and movement of seawater incorporates: chemistry, physics, geology, & bio Meteorology - study of the atmosphere, weather, and climate Astronomy – study of the universe all objects in space, including earth

Formation of Earth 1.1 1 of 9 (or 8) planets Solar system = orderly Formed during same span as other planets and from the same material as the sun Nebular Hypothesis – bodies of solar system evolved from enormous rotating could, the solar nebula made mostly of H & He

http://daphne.palomar.edu/lyon/Animations/NebHypo.swf

Nebular Hypothesis 1.1 Look at Picture on Page 4 What do all the stages of this hypothesis have in common? What was the first stage in the development of our solar system? While Earth formed, denser materials sank to Earth’s core while less dense materials escaped to the atmosphere

Layers Form on Earth 1.1 Earth Formed Radioactive element breakdown (decay) Heat released (from all the colliding particles) Melting of the interior Denser element (iron and nickel) sink to center Lighter/rocky float outward Still believe to occur Atmosphere forms from gases escaping

A View of Earth 1.2 Earth’s Major Spheres 3 major PHYSICAL Environment Hydrosphere – water portion Evaporates  falls back as precipitation  runs back to rivers/oceans/etc Oceans = 97% of water on Earth 3% = groundwater, streams, lakes, and glaciers Important b/c the sustain life and help create land forms

Atmosphere Geosphere Gaseous envelop 100 km above earth 90% just within 16 km of earth Provides air we breath protects Geosphere Not uniform Core – heavy dense inner core Mantle Crust – lighter – not uniform Thinnest beneath the ocean Thickest beneath continents Lithosphere – uppermost mantle Asthenosphere – below lithosphere - molten rock

Biosphere – all of life on earth 4th major sphere Biosphere – all of life on earth Ocean floor and upward for several km into the atmosphere

Plate Tectonics 1.2 Grand Canyon, the Rocky Mountains, and the Appalachian Mountains did not exist a billion years ago Destructive forces – weathering, erosion (wear away land) Constructive Forces – mountain building and volcanism (raising the land) Revolution – learning more about Earth Idea that continents moved the face of the Earth = PLATE TECTONICTS Earth broken at lithosphere into plates Motion caused from uneven heating of earth’s surface = earthquakes, volcanic activity, rocks into mountains

Representing Earth’s Surface 1.3 Global Grid Latitude (fatitude) – distance N or S of the equator (0o latitude) – lines run E and W Longitude – Distance E or W of the prime meridian (0o longitude) – lines run N and S Earth is 360 degrees around Equator divides Earth in 2 hemispheres Northern and southern Prime Meridian divides earth in 2 hemispheres Eastern and western

Globes 1.3 Shapes, sizes of islands, continents, and bodies of water Found by exploring Best represented thru a globe Earth is round

Maps and Mapping 1.3 Flat representation of Earth’s surface Can not be accurately represented Too small, big, out of place The Mercator Projection Gerardus Mercator made map in 1569 to help sailors navigate Lines of longitude are parallel (compare to globe) Makes grid rectangular Bonus: showed directions accurately Negative: sizes and distances distorted (esp around poles)

The Mercator Projection

Different Projection Maps for Different Purposes 1.3 Best project determined by use Robinson Projection – widely used Bonus: show most distances, sizes, and shapes accurately Negative: distortions around the edges Conic Projection – wrap a cone of paper around a globe at line of latitude, trace Almost no distortion at line of latitude High distortion away from latitude line Accuracy great over small area (used for maps) Gnonomic Projection Place piece of paper on globe so it touches since point Distance and direction distorted Useful to sailors to show shortest distance between 2 oints

Topographic Maps 1.3 Represent Earth’s 3-D surface in 2-D Show elevation by contour lines Also can show water, roads, gov and public buildings, political boundaries, and places names Contour Lines – every position along a single contour line is the same elevation Every 5th line is bolded = index contour Closer together line = steep slope Farther apart lines = gentle slope Never touch or intersect Depression = circular contours that have hachure marks – small lines on circle that point to the center

Scale of Topographic Maps 1.3 Determine distances on the map and relate them to the real world Certain distance on the map is drawn to equal a certain distance on the surface 1:24,000 = ratio Has no units 1 unit on map is equal to 24,000 units on the ground

Geologic Maps 1.3 Shows type and age of the rocks exposed Each rock formation assigned a color and sometimes a pattern

Advance Technology 1.3 Gives us the ability to more precisely analyze Earth’s physical properties Use satellites and computers Remote sensing – process of collecting data about Earth from a distance

Technology and Earth Science 1.3 Weather Satellites – monitor temp, humidity, & clouds Navigation Satellite – assists ships and submarines Landsat Satellite – Data on Earth’s landmasses, coastal boundaries, and coral reefs  complete 14 orbits per day GPS - Combines satellite with computer technology providing latitude, longitude, and altitude Very Long Baseline Interferometry – measures the geosphere – study tectonic plates

Earth System Science 1.4 Look at earth as a system made up of numerous interacting parts Tries to study all branches of science What is a System? Any size group of interacting parts that form a complex whole. Closed System – no matter enters or leaves the system; energy moves freely Open System – both energy and matter flow into and out of the system Most natural systems

Earth as a System 1.4 Earth powered by energy from 2 sources Sun – drives external processes (weather, climate, ocean circulation, erosion processes) Earth’s interior – from radioactive element and from time Earth formed power internal process = volcanoes, earthquakes, and mountains Change in one system affects the other Volcano erupts  lava flow block nearby valley  influence drainage system  ash influences solar energy = drop in temp. Our actions produce changes in all parts of Earth’s system

People and the Environment 1.4 Environment – everything that surround and influences an organism Biological or social Nonliving = physical environment = air, water, soil, rock, temp, humidity, sunlight Environmental Science – focus on relationships between people and the natural environment

Resources 1.4 Water and soil, metallic and nonmetallic minerals, and energy Foundation of modern civilization RENEWABLE resource – can be replenished in a short period of time Plants and animal food, natural fibers, lumber, paper, water, wind, and the sun NONRENEWABLE – process to create sources takes millions of years Iron, aluminum, copper, oil, natural gas, coal

Population 1.4 Growing rapidly Population increases, demand for resources increases Yet, energy resources do not increase Leads to many questions How long will the remaining supplies of basic resources last? How long can we sustain the rising standard of living in today's industrialized countries? How much environmental deterioration are we willing to accept to obtain basic resources? Can alternatives be found?

Environmental Problems 1.4 Air pollution Acid rain Ozone depletion Global warming Loss of fertile soils to erosion Toxic waste Depletion of water resources Natural hazards: earthquakes, landslides, floods, hurricanes, drought Knowledge about Earth and how it works is necessary to our survival and well being

What is Scientific Inquiry? 1.5 Science based on 2 assumptions: Natural world behaves in a consistent, predictable manner Careful, systematic study can explain the natural world’s behavior Basics steps to the scientific method Collect data thru observation and measurement (Question) Hypothesis (1 or more working hypothesis) Test and Analyze Conclusion = acceptance, modification, or rejection of hypothesis

Scientific Inquiry 1.5 Theory Made after hypothesis has been tested extensively and competing hypothesis eliminated well tested and widely accepted by scientific community EXPLAINS observable facts