GEOG_1113_Exam_1_Study_Guide_PDF.pdf GEOG 1113
Popular in Introduction to Landforms
Popular in Geography
This 8 page Study Guide was uploaded by Samantha Snyder on Monday October 3, 2016. The Study Guide belongs to GEOG 1113 at University of Georgia taught by Brooks in Fall 2015. Since its upload, it has received 3 views. For similar materials see Introduction to Landforms in Geography at University of Georgia.
Reviews for GEOG_1113_Exam_1_Study_Guide_PDF.pdf
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 10/03/16
GEOG 1113 Exam 1 Study Guide Brook 1. The density of the inner core of the earth • Crust – 2.8 gm/cc Upper Mantle – 4.0 gm/cc Lower Mantle – 5.0 gm/cc Outer Core – 11 gm/cc TRANSITION ZONE Inner Core – 15 gm/cc 2. According to Bullard and his co-workers, the true edges of the continents are located at… • 3000 ft on the continental slope 3. The temperature of molten Lava is • 900-1200 degrees Celsius 4. The inclination of the magnetic lines of force at the equator is… • 0 degrees 5. Continental crust is generally older than… • 550 million years old o called SIAL, made mostly of silicon & aluminum • Oceanic Crust: 65-190 million years old o Called SIMA, made mostly of silicon and magnesium 6. The boundary between the core and the mantle of the earth is called • Oldham/Gutenberg Discontinuity • Boundary between crust and upper mantle —Mohorovicic Discontinuity 7. We are presently in an epoch when the earth is normally magnetized. Between 2.5 and 4 million years ago, the earth was also normally magnetize d. The name of this epoch is • Gauss Epoch • 4MA—Gilbert Epoch—reversed 2.5-3.4MYA—Gauss Epoch—normal 700,000yrs-2.5MA—Matayuma Epoch—reversed Now-700,000yr—Bruhnes—normal 8. In what year did the volcano Krakatau erupt? 1883 9. Striations in rock often have one b lunt end and one sharp end. Which way does the blunt end point? • Up-glacier (opposite direction of flow) • Pebbles get frozen in ice, glacier moves along the bedrock & scrapes (creating glacial striations), pebble eventually loosens and gets carried up into the ice 10. The anticenter of the earth receives P waves. 11. 250-300 million years ago the east side of Pangaea was indented by a sea called the —Tethys Sea • Laurasia – Northern Hemisphere • Gondwanaland – Southern Hemisphere • Iapetus Sea—pre-atlantic ocean floor • India attaching to Asia caused “suturing” (mountain formation) 12. When a volcano erupts and pieces of the volcanic cone are broken off and are thrown into the air these are called o 3 kinds § Essential – derived from present magma § Accessory—blown off during eruption—old material § Accidental—not part of volcanic event, local rock broken up by accident & thrown o Volcanic bombs (big pieces of molten rock flown from eruption) —surtsey 1964 off Iceland o Lapilli—lead-shot or pea-sized fragments o Dust—volcanic veil theory § Records of volcanic eruption history can be found in ice sheets o Tuffs (pyroclastic layer) and pumice 13. The point of origin of an earthquake is called —focus 14. Which of the following plate names is not correct? 6 Plate names highlighted in class — African Plate, Pacific Plate, Eurasian Plate, Antarctic Plate, Australian Plate, American Plate 15. Which seismic waves reach all parts of the earth? 16. The mean density of the earth is —5.5 gm/cc • Density of surface rocks 2.8 gm/cc 17. Earthquakes are produced by movements along faults. 18. What kind of volcano is Mauna Kea in Hawaii? – Shield • Mt. Etna is a composite volcano with secondary cones 19. Eruption of the volcano of Krakatau killed people because of tidal waves . 20. Largest volcano in the universe Olympus Mons on Mars >700 km in diameter, 25 km from base to summit 21. What do we call a mudslide that is associated with a volcanic eruption ? • Lehar 22. Who is considered to be the father of t he theory of continental drift • 1915 – Wegener – suggested rocks had been pushed upwards AND moved horizontally 1930—claimed all continents used to be one: idea of Pangea emerged 23. If we want to know how far away an earthquake epicenter is from a seismogram station, how many seismograph s do we need? 3 24. After an earthquake there is always a shadow zone. Seen from above the anticenter, the shadow zone is in the shape of – a donut 25. What kind of eruption killed many of the inhabitants of Pompeii and Herculaneum in 79 AD? • Volcanic ash—pyroclastic eruption Other Types of Eruptions • Flank eruptions à parasitic/secondary cones (usually more common than a central vent eruption) • Effusive eruptions: o Lava has low silica content. These are mainly found in ocean areas • Explosive eruptions o When lavas have high silica content. These are usually on continents/on land • Central-Vent volcanoes o This is what we are most familiar with. This is how volcanoes in the U.S are like and they are very common. • Fissure eruptions and flood basalts o EX: Drakensberg mountains, south Africa, shows the layer upon layer of flood basalt. Columnar basalt lies over Yellowstone national park • Kimberlite pipes • Plutons o When melting materials rise but for some reason doesn’t break surface —cools as it rises & solidifies (stone mountain) 26. How do we date very old rocks tens to hundreds of millions years old? 27. Yellowstone National Park is northwest Wyoming is above what geologic feature? • Hotspot // mantle plume 28. An eruption produces a lava flow 120 ft thick. What kind of lava was eru pted? • Block lava Type Appearance Content Thickness Flow speed Additional Info AA Blocky Low silica 5-20ft >10mph content Pahoehoe Wrinkly, ropy, shiny Low silica 5-20ft 30-40mph Forms lava content, tubes low gas content Block Angular, thick, sticky High silica Can exceed 200ft Very slow content, acidic 29. How deep is an ocean trench? • 23,000 ft deep • Ocean trenches are subduction zones & ocean ridges are sea -floor spreading zones 30. Where do we find guyots? • Deep sea floor – ocean floor spreading Other Information • Seismic Waves Waves Speed Direction of Materials they Other info Motion pass through P waves (primary) ~4.8 mi/sec Left to right Deep into/around Sound travels like (push/pull) earth P waves Causes particles to vibrate S Waves ~2.7 mi/sec Perpendicular or Only through (shear/secondary) transverse solids Particles move in Deep into/around a right angle to their path L waves (long) ~2.5 mi/sec Counter OR Move through Ocean waves clockwise surface material travel this way Particle movement is elliptical • Earthquake Examples o 1989 San Fran – 7.1 on Richter scale o 1899 Alaska – 8.6 • Glacial Till Fabric o “till” or “boulder clay” § Soft material that glaciers flow over o Tillites: glacial till that gets cemented over time o Common examples: calcite an d silica § Dwyka tillite in South Africa • Paleomagnetism o Remnant Magnetism § Thermal remnant magnetism (TRM) § Depositional remnant magnetism (DRM) o Magnetism in rocks § Curie temperature = 700 degrees Celsius (rocks lose magnetism) § Lava has a temp of ~900-1200 degrees Celsius § As lava cools, it acquires magnetic properties àremnant magnetism, an imprint of the earth’s magnetic field at the time of lava flow § Ppl can calculate old latitudes by using the magnetic lines of force from rocks in the area (evidence of continental drift) o Remnant magnetism suggests a wandering magnetic pole • General Magnetism o Magnetic pole reversals ** know periods (Bruhnes —Gilbert) • Plate Tectonics o Dan Mckenzie (wears glasses) worked with grad student Edward Bullard § 1968—Plate Tectonics Theory § Movement driven by convection currents in mantle o Mid Ocean Ridges: >27,000 ft high o Deep Ocean Trenches: >23,000 ft deep o Magnetic Lineation on ocean floor is evidence of sea floor spreading • Ocean Mountains o Seamount—rounded top o Guyot—flat top (volcano grew, rose above sea level, ocean surface eroded it flat, sea floor spreading caused it to sink) • Volcanic Forms o Ring Crater § Typical of continental areas with silica rich ground § Gasses migrate to surface, pressure increases § As they escape, massive reduction in pressure & surface rocks fragment, creating a depression and sends pyroclastic material up/out in a ring shape § Ex. Zuni salt lake, NM o Ash/Cindercone § Steeper by vent § Wind direction affects the way ash falls àsize/shape of cinder cone § First feature to arise in volcanic activity § Soda pop bottle effect: pressure increases bc of rising temperature, material becomes bubbly, when it gets closer to the surface the pressure decreases causing an explosion § Ex. Harrat al Kishb in Saudi Arabia o Composite Volcano § Mixture of lava and ash, often in different layers § Most common on land masses § Ex. Mt Rainer, Mt St Helens, Mt Hood, Mt Shasta, Mt Fugi, Mt Vesuvius, Goma volcano § Paricutin in Mexico—1943, cindercone grew 120 ft in 24 hours composite volcano @ 1,350 ft high by 1952 o Cumulo Domes or Lava Domes § Built of block lava so the lava flows a short distance from the central vent § Examples in france o Shield volcanoes § AA or Pahoehoe lava § Lava flows great distances from central vent § Broad, low structures § Hawaii – Mauna Loa
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'