Astronomy: 1. What is the shape of the earth and why is it this shape? The Earth is not a perfect sphere. Due to its rotation, the Earth (like all rotating planets) has a slightly distorted shape. The rotational momentum tends to force the matter to bunch up in the middle. In the case of the Earth, this "middle" is the equator. The true shape of the Earth is called an Oblate Spheroid. 2. Describe the theory used to explain how the universe began. About 15 billion years ago a tremendous explosion started the expansion of the universe. This explosion is known as the Big Bang. At the point of this event, all of the matter and energy of space was contained at one singular point. What existed prior to this event is completely unknown, and is a matter of pure speculation. This occurrence was not a conventional explosion, but rather an event that filled all of space with all of the particles of the developing universe rushing away from each other. This event forced the galaxies to not be clumped together, but rather spread apart. The origin of the Big Bang theory can be credited to Edwin Hubble. 3. What is the process that generates energy in a star and which elements are involved? Nuclear Fusion. This process converts the nuclei of 4 Hydrogen atoms into 1 Helium atom. Because the mass of 4 Hydrogen atoms does not equal that of 1 Helium, the excess mass is released in the form of energy (heat). 4. Describe the following: nebula, red giant, white dwarf, nova, black hole Nebula = a cloud of dust and gas that contains all of the necessary components to form a star. Red Giant = the evolutionary stage that directly follows the main sequence stage, when a star will begin to convert Helium into Carbon. The size will increase dramatically and the temperature will drop due to the increased size. White dwarf = following the Red Giant stage when a star has exhausted its nuclear fuel the star will collapse, expelling a planetary nebula, and form the white dwarf. This star is dim due to the size, but it burns very hot. Nova = when the gases surrounding a white dwarf will ignite and burn brightly. This causes a significant increase in the brightness of a star. Not to be confused with a supernova. Black Hole = following a tremendous explosion (supernova) a super-massive star will collapse into itself a form a center of gravity so strong that not even light itself can escape. 5. List the sun s outer three layers. Which one do we see? Corona Chromosphere Photosphere The Corona and Chromosphere can only be seen during a total solar eclipse. The photosphere is usually the only visible layer due to the brightness. 6. Describe the following: sunspot, solar flare Sunspot = a cool dark area on the surface of the Sun. Due to magnetic forces. Solar Flare = an explosion on the surface of the Sun that releases solar particles (ions) through solar winds.
7. Draw & label a picture of a solar eclipse and a lunar eclipse. 8. Draw & label the 8 phases of the moon.
History of Earth 1. The Giant Impact Hypothesis: A Mars-sized object hit Earth early in its formation, ejecting material into orbit which accreted into the Moon. 2. Indirect estimates (relative dating) and Quantitative methods (e.g. radiometric dating) 3. Fossils: Traces of past life; Sedimentary rocks (found in rock layers) 4. Index fossils are distinct, widespread, and short-lived fossils that are used to help determine the age of a rock layer. 5. Original horizontality; Superposition; Lateral Continuity 6. Using radioactive material to determine the age of rocks 7. First humans: 65 mya Plate Tectonics 1. The Theory of Continental Drift, developed by Alfred Wegener, stated that all the continents had once been joined in a supercontinent called Pangaea. Evidence that supported included the fit of the continents, matching fossils on different continents, similar rocks and structures on appear on unconnected continents, and ancient climates very different from current climates (glaciers in South America, Africa, India, and Australia) 2. Divergent: plates move apart and new crust is formed; mid-ocean ridge, rift valley, seafloor spreading Ex. Mid-Atlantic Ridge Convergent Oceanic-oceanic: one ocean plate subducts under other as they move together; Subduction zone, trench, volcanic island arc ex. Japan Oceanic-continental: ocean plate subducts under continental plate; Subduction zone, trench, continental volcanic arc ex. Andes Continental- continental: plates push together and both are bent upwards; mountains ex. Himalayas Transform Fault: plates move past one another without creating or destroying crust; associated with earthquakes ex. San Andreas, CA 3. Compressional stress: rocks are shortened or squeezed Tensional: rocks are stretched or undergo extension Shear: rocks are distorted with no change in volume 4. Fault: Fractures in the crust along which movement has occurred
5. Normal fault: hanging wall moves down relative to foot wall; occurs due to tensional stress Reverse fault: hanging wall moves up relative to foot wall; high angle fault with dip greater than 45 (movement is mainly vertical); occurs due to compressional stresses Thrust fault: reverse faults with dips less than 45 (movement is more horizontal than vertical); occurs due to compressional stress Strike-slip: movement is horizontal and parallel to the fault surface; commonly caused by shear stress 6. Fold bending of rock without folding 7. Rift valley: deep faulted structures found along the axes of divergent plate boundaries; can be found on seafloor or land but always at divergent boundaries 8. Fault-block mountains (grabens and horsts): a mountain formed when large block of crust are tilted, uplifted or dropped between large normal faults 9. Isostasy: the concept that Earth s crust is floating in gravitational balance upon the material of the mantle 10. Plate: separate pieces of the lithosphere; Earth s surface is divided into over 30 plates 11. The lithosphere consists of the crust and uppermost mantle while the asthenosphere consists only of the lower part of the upper mantle. The lithosphere is rigid and brittle while the asthenosphere is plastic rock (it slowly flows under pressure). Tectonic plates are made of lithosphere and float on the asthenosphere.
12. Long Waves (L-Waves) Travel along the surface of the Earth, also move EARTHQUAKES: 1. The vibrations of the earth caused by the rapid release of energy. 2. Focus The point within the Earth where an earthquake first occurs. Epicenter The location on the Earth s surface directly above the focus. 3. Foreshock A small earthquake that often precedes a major earthquake. Aftershock A small earthquake that follows the main earthquake. 4. A fracture is a crack in the earth s crust; when movement occurs along a fracture it becomes a fault. 5. Primary Waves (P-Waves) Carry the most energy, travel the fastest and reach seismic stations first. P-waves can travel through solids, liquids and gases. Secondary Waves (S-Waves) Shake particles at a right angle to the direction of the energy. S-waves travel through solids only and arrive at seismograph stations second. the slowest. Create the most damage of the three waves. 6. Intensity Measured with the Mercalli Scale (I-XII), amount of damage Magnitude Measured with the Richter Scale (0-9.99), amount of energy 7. Major earthquake zones: Circum-Pacific Belt, Mediterranean-Asian Belt, Oceanic Ridge Systems 8. Layers of the Earth: Inner core, Outer core, Lower mantle (asthenospehere), Upper mantle & Crust (lithosphere) 9. Seismograph Instrument that records earthquakes. It takes the energy released and translates it into a series of electrical impulses that are then recorded onto a roll of paper. 10. Tsunami- The Japanese word for a seismic sea wave. 11. Predicting Earthquake: change in P-Wave motion, Seismic gaps, tilting, foreshocks.
VOLCANOES 1. Magma is molten rock below the Earth s surface, it becomes lava once it breaks the Earth s crust. 2. Shield Cone: Broad base, gently sloping sides, quiet lava eruptions Cinder Cone: Narrow base, steep sides, explosive lava eruptions Composite Cone (strato): Combination of shield and cinder, both quiet and loud eruptions. 3. Mafic: Dark in color due to Mg and Fe. Thin/watery, from oceanic crust Mid Ocean Ridge: Plates move apart and magma forms new ocean floor. Ex.) Mid Atlantic Ridge, Iceland 8. Hot Spots: Area NOT on a plate boundary. (intraplate volcano) Area is so hot so when plate moves volcano becomes inactive and a new volcano forms. Ex.) Hawaii 9. Circum Pacific belt of volcanoes found in Pacific Ocean 10. Predicting Volcanic Eruptions: Seismographs, Bulging Surfaces, Change in Composition of Volcanic Gasses. comes out in quiet eruptions Felsic: Light colored due to Silica. Thick with trapped gasses and water, from continental crust comes out in explosive eruptions. 4. aa: Sharp and jagged when hardened Pahoehoe: wrinkled and ropey when hardened 5. Tephra: rock fragments that are ejected during an eruption 6. Crater: Funnel shaped pit at the top of a vent Caldera: Large basin shaped depression formed when volcanic cone is empty and collapses. 7. Subduction Zones: One plate moving under another forming volcanic mountains. Ex.) Pacific Ring of Fire
Minerals: Rocks: 1. Rules to determine if a substance is a mineral? (SNIFE) S = solid N = naturally occurring I = inorganic F = fixed crystalline pattern E = element or compound 2. Six characteristics of minerals describe each that was used in our labs Color = (not a useful test for most minerals) the color a mineral appears to have Streak is the color of a mineral in its powdered form. Luster is used to describe how light is reflected from the surface of a mineral. Crystal form is the visible expression of a mineral s internal arrangement of atoms. Hardness is a measure of the resistance of a mineral to being scratched. (The Mohs scale consists of 10 minerals arranged from 10 (hardest) to 1 (softest).) Cleavage is the tendency of a mineral to cleave, or break, along flat, even surfaces. Fracture is the uneven breakage of a mineral. Density is a property of all matter that is the ratio of an object s mass to its volume. (Density = mass/volume) Special Properties - Some minerals can be recognized by other properties, such as fluorescence, magnetism, reacts with acid, smell, and double refraction. 3. Groups of minerals define and discuss examples Silicates are minerals that contain silicon and oxygen (most common group) Carbonates are minerals that contain the elements carbon, oxygen, and one or more other metallic elements. Oxides are minerals that contain oxygen and one or more other elements, which are usually metals. Sulfates and sul-fides are minerals that contain the element sulfur. Halides are minerals that contain a halogen ion plus one or more other elements. Native elements are a group of minerals that exist in relatively pure form. 1. Rock Cycle: 2. Types of Igneous Rock: Intrusive: Cools slowly within Earth, large crystals. Extrusive: Cools quickly on surface; no crystals. 3. Sedimentary rocks: Clastic: Made of rock fragements. Bioclastic: Made of organic sediments (usually remains of ocean animals) 4. Metamorphic rocks: Foliated: Has visible layers. Non-foliated: No visible layers 5. Sandstone Quartzite Limestone Marble Shale Slate Phyllite