GEOL 1425 1nd EditionExam # 1 Study Guide Lectures: 1-5Lecture 1 (January 14)1. The Nebular Hypothesis explains how the solar system may have formed, the Sun being at its center. Starting closest to the Sun, the order of the planets is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto. The first 4 planets are small and rocky, and the last 4 are gaseous with rocky cores. Pluto is different in that it is a snowball of methane, water, and rock.2. Gravitational differentiation produced a layered Earth. This process was driven by gravity. Earth is comprised of a core, mantle, and crust surrounded by a fluid ocean and a gaseous atmosphere. Transformation of primordial matter chunks from the gravitational differentiation helped to transform the Earth from a hot and rocky mass into a living planet with continents. 3. The moon was once part of the Earth.The moon was thought to be created when early Earth was hit by a large body and then fragmented. The fragments remained in orbit and eventually congealed to form the moon. The light portions of the moon are lunar highlands, dark areas are the maria.The moon, though made from chunks of Earth, has remained inactive and unmodified/stable forhalf of its lifetime. Earth’s crust has been recycled.4. The age and complexion of the all the planetary surfaces are all different. Each planet’s age and complexion can be explained by how far it is from the Sun and what it is made out of. Lecture 2 (January 16)I. Concept 1: The Earth’s Shapea. Geodesy- the study of Earth’s shape and surfaceb. Erathosthenese was an ancient Greek scholar who showed that the Earth was spherical. c. Earth is not flat, but also not a complete perfect sphere. It bulges at the equator and somewhat flattened at the poles because of rotational momentum.II. Concept 2: The Geologic Recorda. James Hutton, an 18th century physician and geologist, came up with the principle of Unitarianism (Geologic processes of today worked much the same way in the geologic past).b. “The present is the key to the past”, meaning that the same processes that have operated in the past will continue to operate in the future. The physics and chemistry remain the same, but the rates of intensity and rapidity may change. c. Geologic record=information preserved in the rocks. III. Concept 3: Discovery of a Layered Eartha. The outer core of the Earth is liquid, while the inner core of the Earth is solid.b. Seismic waves illuminate Earth’s interior. Compression and sheer waves behave differently and are bent or absorbed at layer boundaries within the Earth. Sheer waves do not pass through liquids.c. The surface rock of the Earth is much less dense than the core rock of the Earth. d. Iron and nickel are in the core of the Earth. At least the outer part of the core is liquid because the S waves in Oldham’s experiment could not compress liquid likethe P waves could. The inner core of the Earth is solid. IV. Concept 4: Earth as a System of Interacting Componentsa. Earth is a restless planet that continually changes though geologic activity (e.g. earthquakes and volcanic eruptions) which is powered by two hear engines—oneinternal and one external.b. The Earth system comprises several substances: plate tectonic and geodynamo system.Lecture 3 (January 21) I. Global Scale of Climate Systema. The climate system includes all the Earth system components that determine climate on a global scale and how climate changes with time.b. Hydrosphere contains how the water cycle affects the Earth’s climatec. Cryosphere contains the ice/frozen water cycle’s effect on climate. EX: water stored as ice sheetsd. Biosphere contains the organisms in Earth and how they affect other climates (desert, tundra, etc.)e. Lithosphere contains the mountains and plate changes, and how these changes affect the climate of the earthf. Plate tectonic system= The forces that push and pull the plates around the surface come from the heat engine in Earth’s solid mantle.II. Greenhouse Gassesa. Greenhouse gasses help to regulate Earth’s climateb. Without them to heat and warm the Earth, the planet would be too cold to live on. This is referred to as the “Greenhouse effect”c. “Snowball Earth” refers to periods of major ice ages, when ice likely covered the entire planet. They reduced the amount of greenhouse gassesIII. Convection currentsa. The convection currents in the mantle are slow motions, and there is no geodymano here. IV. Geodynamo system= This global geosystem involves interactions that produce a magnetic field deep inside the Earth, in its fluid outer core.V. Stromatolytes= layered accretionary structures s formed in shallow water by the trapping, binding and cementation of sedimentary grains by biofilms of microorganisms.Lecture 4 (January 23) II. Start of Plate Tectonicsa. lithosphere— Earth’s strong, rigid outer shell of rockb. Plates embedded in the Lithosphere are moving around causing continental drif. This is the process of mountain building! c. Plate tectonics: plates moving around. Mountain building, where volcanoes and earthquakes erupt, and different rock formations can all be explained by plate tectonics. III. Plate tectonic theories and theoristsa. Continental drift= large-scale movements of continents all over the globe. b. The first idea of plate tectonics (which wasn’t completely correct), said that the lithosphere was made of a series of plates. New theory: created 40-50 years ago post World War II where much of the ocean seabed was mapped and when manynew ideas came together.c. One new theory—“Contraction Theory”—the surface of the Earth contracted andwas thought to have shrunk (a good visual is of a plum drying up and turning intoa prune). Problem with this theory was that the dates of the land did not come together (the mountain tops should all be the same height/date but they are not)d. Orteilus thought that Africa and South America were once attached and torn away from each other by earthquakes and floods… that continents were once joined!e. “Jigsaw puzzle” – rocks and other geological evidence suggest that Earth may have once been a supercontinent because when we put the continents together their coastlines all seem to match up. We call this once-supercontinent “Pangaea”. f. Wegener is an un-sung hero of this theory! He was a meteorologist, so other geologists thought “what is he doing in geology? He