Download Chapter 9 :: The Wrath of Vulcan: Volcanic Eruptions

GLY1101
Dr. Scott T. Marshall
Exam III Review Sheet
Disclaimer: This review sheet is an attempt to help you to realize what topics are most important and thus most likely to appear on
the exam. This review sheet is not meant to be a direct listing of the questions that I will ask on your exams. This review sheet is
much longer than what your actual exam will be. The purpose of this course not to memorize a list of terms and then take an exam
on that list. The purpose of this course is to learn about geological concepts and then to use your knowledge to critically think
about the implications for the Earth and the world around you. Keep these thoughts in mind as you prepare for the exam.
Chapter 9 :: The Wrath of Vulcan: Volcanic Eruptions
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Lava Flows: What are the basic properties of basaltic/mafic, intermediate/andesitic, and rhyolitic/felsic flows ?
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what are pahoehoe and aa? What kind of lava to they apply to?
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Columnar joints…describe them and how they form
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Pillow basalts…what are they and where do they form?
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Lava domes…what kind of lava? What do they cause in terms of eruption behavior?
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Pyroclastic debris…know the various components, what they are made of, and be able to describe/compare them.
What kinds of rocks form from lithified pyroclastic debris?
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Features of an explosive eruption? Pyroclastic flows?
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Blocks vs. bombs? How do they differ?
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Ash fall vs pyroclastic flow…what is the difference?
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Lahars? What are they and why do they form?
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Volcanic gas…what is the effect of gas, what does gas do to eruptions and what evidence do we see in rocks to
suggest gas in ancient eruptions? What rocks form because of lava with abundant gas?
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Scoria vs. Pumice? How are they similar and how are they different?
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Do all volcanic eruptions emanate from a vertical pipe-like structure?
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Magma chambers? Craters + Calderas? Differences?
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Volcano morphologic types: describe and identify the three types…how is each formed?
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What factors control eruptive styles of volcanoes? Effusive, explosive, phreatomagmatic...etc.
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Which types of eruptions happen at subduction zones? Divergent? Hot spots (continental and oceanic)?
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Why are there volcanoes in Hawaii and Yellowstone? Why do these volcanoes behave so differently?
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Know the basic types of hazards the volcanoes pose to society.
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How do we monitor volcanoes?
Chapter 10 :: A Violent Pulse: Earthquakes
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What types of geologic phenomena produce earthquakes?
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Hypocenter, Epicenter, Focus, what are they?
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Be able to name and describe the various types of faults (reverse/thrust, strike-slip, normal, oblique)
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Hanging Wall and Footwall: be able to identify and describe them.
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How do you describe the motion of a strike-slip fault? (hint: they do not have a hanging wall or footwall)
GLY1101
Dr. Scott T. Marshall
Exam III Review Sheet
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What fault type accommodates contraction? What type accommodates extension?
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What are the terms that describe the motion along a fault (slip, displacement, offset).
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What is a fault trace? What about a fault scarp? What about a blind fault?
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What causes a fault to form?
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What causes friction? What are asperities?
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Be able to describe stick-slip behavior and why it causes earthquakes. Do all faults have stick-slip behavior? What is
fault creep? What does aseismic mean?
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What is meant by stress drop? What event happens during a stress drop?
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What are body waves and surface waves? Are S-waves the same thing as surface waves?
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What are shear waves and compressional waves and how does a particle move in these different types of waves?
What are P-waves? S-waves? R-waves? L-waves?
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Know the 4 types of waves generated in an earthquake. Which arrives first? Which arrives second? Which is most
destructive? Be able to describe the motion of particles in each of these waves.
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Since P-waves and S-waves travel at different speeds, they arrive at seismographs at different times…In what way are
the arrival times of these waves useful?
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What is triangulation? What does it tell us and why aren’t arrival times at a single location enough to locate an
earthquake?
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What exactly does a seismograph measure?
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What is the Mercalli Intensity scale? Does the Mercalli scale vary with location in a given earthquake?
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There are various types of magnitude measurements…be sure to know Richter magnitude (M L) and moment
magnitude (MW) and be able to describe why we have different ways of measuring magnitude.
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What controls the magnitude of an earthquake? (hint: there are three factors, but only two really matter)
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All magnitude scales are logarithmic…what does that mean? Why do we use a logarithmic scale?
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At what type of geologic settings do most earthquakes occur?
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Know the differences between divergent, transform, and convergent boundary earthquakes. Which typically cause
tsunamis? Which cannot cause a tsunami?
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Which plate boundary has the greatest potential for large earthquakes? Why? Which one has the shallowest
seismicity? Why? Which has the deepest? Why?
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What are intraplate earthquakes? Are they felt over the same distance as plate boundary (interplate) earthquakes?
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What does anthropogenic mean? What are potential causes of anthropogenic earthquakes?
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What factors influence the severity of shaking at a given location during an earthquake?
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What is liquefaction?
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What is a tsunami? What is required to create a tsunami? Why is tidal wave a bad name for tsunami?
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Are tsunamis dangerous to boats far out at sea?
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How does a tsunami wave change in wavelength and amplitude from the deep sea to shore?
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How are tsunami waves different from normal wind created waves? Why does this matter?
GLY1101

Dr. Scott T. Marshall
Exam III Review Sheet
What is the difference between short term and long term predictions of earthquakes? Can seismologists/geologists
make reliable short term predictions? What about long term predictions?
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What is a seismic gap?
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What is stress triggering or triggered seismicity?
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What is the difference between seismic risk and seismic hazard?
Interlude D: Seismic Waves
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What does the speed of seismic waves through various rock types tell us about the rocks?
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What can s-waves not travel through that p-waves can?
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What is the difference between reflection and refraction?
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How was the Moho discovered?
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Are seismic velocities constant with depth in the Earth? Why do seismic waves travel in curved paths?
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What is the low velocity zone? What does this low velocity imply about the rocks at this depth? Why is this zone
important for plate tectonics?
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What is a seismic discontinuity? Do seismic velocities generally increase or decrease with depth in the Earth? Are
there exceptions?
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What are shadow zones? What causes the p-wave shadow zone? What causes the s-wave shadow zone?
Chapter 12 :: Deep Time: How Old is Old?
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What are body fossils and trace fossils? How are they different?
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What environmental characteristics are necessary for a fossil to be preserved?
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What is (phyletic) gradualism? What is punctuated equilibrium? How do these terms relate to evolution?
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What is the principle of uniformitarianism?
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What is the difference between relative age and numeric age?
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What is the principle of superposition? What kinds of rocks does it apply to?
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What is the principle of original horizontality? What kinds of rocks does it apply to?
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What is the principle of original continuity?
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What is the principle of cross-cutting relations? To what kinds of geologic features does this principle apply?
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What is the principle of inclusions?
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What is the principle of fossil succession? What are index fossils?
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Be able to name, recognize, and describe the three types of unconformities
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What is lithologic correlation? When units thin and disappear they are said to _____ _____?
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What types of information are on geologic maps? In what way(s) does a geologic map have more info than a
topographic map?
GLY1101
Dr. Scott T. Marshall
Exam III Review Sheet
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What is geochronology? What is radiometric dating?
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Be able to explain and determine how half-life and parent-daughter ratios can tell the age of a sample. Also, be able
to calculate age from a parent-daughter ratio given some half life value.
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What is blocking temperature? What does a radiometric date of a volcanic rock tell you? What about a radiometric
date of a sedimentary rock? What about a radiometric date of a metamorphic rock?
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Is carbon dating useful for dating most rocks? Why?
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How can geologists date layers of glaciers?
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What is magnetostratigraphy?
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Why haven’t geologists ever found and dated a rock that is 4.6 Ga (the age of the Earth)? The oldest known rocks are
~4.2Ga, so why do we think that the Earth is 4.6Ga?