© 2011 Pearson Education, Inc. CHAPTER 1 Introduction to Planet “Earth”

© 2011 Pearson Education, Inc. Course Overview 40% Plate tectonics and geology these provide the containers the ocean. 40% whats in the container? Seawater, Currents, Waves Tides, Coastlines 20% How do these effect the organisms?

© 2011 Pearson Education, Inc. Earth’s Oceans Oceans are 71% of Earth’s surface. Four (plus 1) oceans –Pacific Ocean –Atlantic Ocean –Indian Ocean –Arctic Ocean –Southern Ocean

© 2011 Pearson Education, Inc. Ocean Size and Depth

© 2011 Pearson Education, Inc. Comparing Oceans to Continents Average ocean depth is 12,234’ Average continental elevation is 2756’ Deepest ocean is the Mariana Trench at 36,161’ Highest continental mountain is Mt. Everest at 29,935’

© 2011 Pearson Education, Inc. The Seven Seas Salty, smaller, shallower than oceans Usually enclosed by land, but directly connected to the ocean 1.Red Sea 2.Mediterranean Sea 3.Persian Gulf 4.Black Sea 5.Adriatic Sea 6.Caspian Sea 7.Indian Ocean

© 2011 Pearson Education, Inc. Pacific Navigators Required extensive travel in open boats and exceptional navigation skills. It was difficult because islands are widely scattered.

© 2011 Pearson Education, Inc. European Navigators Phoenecians – first from Western Hemisphere to develop navigation arts –Navigated circa 2000 B.C. –Explored Mediterranean Sea, Red Sea, and Indian Ocean –First circumnavigation of Africa

© 2011 Pearson Education, Inc. European Navigators Greek Pytheas –Sailed northward using a simple method to determine latitude in 325 B.C. –Navigated using the North Star Eratosthenes determined Earth’s circumference fairly accurately.

© 2011 Pearson Education, Inc. The Middle Ages Vikings explored North Atlantic Ocean –Settled Iceland and Greenland in 9th and 10th centuries A.D. –Greenland, Iceland settlements abandoned by 1450 A.D. due to climatic cooling

© 2011 Pearson Education, Inc. Viking Routes and Colonies

© 2011 Pearson Education, Inc. The Age of Discovery in Europe 1492–1522 Search for new Eastern trade routes by sea, they –Europeans explore North and South America -Christopher Columbus was financed by the Spanish to find new trade routes to Asia. Late 1400’s -Spaniard Ferdinand Magellan circumnavigated the globe. Early 1500’s -Voyages paved the way for the Spanish to take gold from the Incas and Mayas.

© 2011 Pearson Education, Inc. Voyages of Columbus and Magellan

© 2011 Pearson Education, Inc. Voyaging for Science Captain James Cook (1728 – 1779) undertook scientific voyages. –Mapped many islands in Pacific –Measured ocean characteristics –Marine chronograph (longitude)

© 2011 Pearson Education, Inc. Kon-Tiki Thor Heyerdahl 1947

© 2011 Pearson Education, Inc. Ra Expedition Thor Heyerdahl

© 2011 Pearson Education, Inc. Scientific Method Natural phenomena governed by physical processes Physical processes similar today as in the past Scientists discover these processes and make predictions Science never reaches absolute truth (but probable truth) Called the scientific method

© 2011 Pearson Education, Inc. The Scientific Method

© 2011 Pearson Education, Inc. Density Stratification High density = heavy for its size Early Earth experienced gravitational separation. –High density materials (Iron and Nickel) settled in core. –Less dense materials formed concentric spheres around core.

© 2011 Pearson Education, Inc. Map Projections

© 2011 Pearson Education, Inc. Mercator Projection

© 2011 Pearson Education, Inc. Formation of Earth and the Solar System Nebular Hypothesis Nebula = cloud of gases and space dust Gravity concentrates material at center of cloud (Sun) Protoplanets form from smaller concentrations of matter (eddies)

© 2011 Pearson Education, Inc. Protoearth Larger than Earth today Homogeneous composition Bombarded by meteorites Moon formed from collision with large asteroid

© 2011 Pearson Education, Inc. Protoearth Radioactive heat Heat from contraction (protoplanet shrinks due to gravity) Protoearth partially melts Density stratification (layered Earth)

© 2011 Pearson Education, Inc. Origin of Earth’s Atmosphere Outgassing – occurred during density stratification –Water vapor –Carbon dioxide –Hydrogen –Other gases Earth’s early atmosphere different from today

© 2011 Pearson Education, Inc. Origin of Earth’s Oceans Permanent oceans formed 4 billion years ago. Outgassed water vapor fell as rain. Salinity developed from dissolved rock elements and volcanic outgassing. –Early acidic rain dissolved more crustal minerals than today. –Lots of vulcanism is the young earth.

© 2011 Pearson Education, Inc. Life’s Possible Ocean Origins Earth’s earliest known life forms are 3.5-billion-year-old bacteria fossilized in ocean rocks. 1.5 to 2.5 billion years ago,increased oxygen changing atmosphere from simple plants. Cyanobacteria adapted and thrived. Life from: Inorganics (Miller)? Outer Space? God? Or God controlled?

© 2011 Pearson Education, Inc. Stanley Miller’s Experiment Organic molecules formed by ultraviolet light, electrical spark (lightning), and a mixture of water, carbon dioxide, hydrogen, methane, and ammonia

© 2011 Pearson Education, Inc. Age of Earth Radiometric age dating –Spontaneous change/decay –Half-life Earth is about 4.6 – 5.0 billion years old.

© 2011 Pearson Education, Inc. Geologic Time Scale

© 2011 Pearson Education, Inc. Radioactive Decay

© 2011 Pearson Education, Inc. Relative Dating