Questions and Answers
What characterizes conservative plate boundaries?
Which layer of the Earth accounts for the majority of its mass?
What is a key factor for determining the age difference between oceanic and continental rocks?
Which major geological event is primarily caused by the sudden release of energy in the Earth?
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Where do the majority of earthquakes occur?
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What type of fault is characterized by tensional stress and occurs at a divergent plate boundary?
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What does the process of Elastic Rebound Theory describe in the context of earthquakes?
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Which seismic wave type is known for being compressional and the fastest?
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What is the hypocenter in relation to earthquakes?
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Which earthquake is known as the notable earthquake of the 20th century in Chile?
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What type of fault is associated with compressional stress and occurs at convergent plate boundaries?
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What phenomenon describes the slowing down and bending of seismic waves as they pass through Earth's layers?
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Which of the following statements about secondary waves (S-waves) is true?
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What was the name of the supercontinent that existed 250 - 300 million years ago?
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Which of the following is a piece of evidence for the Continental Drift Theory?
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Which geological evidence supports the idea of a jigsaw fit between continents?
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What are the two main landmasses formed after the breakup of Pangaea?
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Which of the following describes seafloor spreading?
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What instrument is used to measure underwater objects and their distances?
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Which type of ridge is associated with seafloor spreading?
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What drives the process of seafloor spreading?
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What characterizes surface waves compared to other types of seismic waves?
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Which seismic wave is known for its elliptical motion?
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What is the purpose of the triangulation method in seismology?
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Who proposed the Gutenberg Discontinuity?
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What caused the discontinuation of Project Moho?
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Which method tracks seismic wave motion during an earthquake?
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What specific area of seismic activity does the Wadati-Benioff Zone relate to?
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What was the main objective of the Hellhole borehole project conducted by the USSR?
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What is the main driving force behind the movement of tectonic plates?
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Which of the following correctly describes the theory proposed by Alfred Wegener?
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What do you call the massive, irregularly shaped slabs of solid rocks that make up Earth's crust?
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During which type of plate boundaries do tectonic plates move towards each other?
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What geological activity is most likely to occur at a convergent plate boundary?
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Which of the following is not considered a primary tectonic plate?
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What type of tectonic plate movement involves magma rising in the gap between plates?
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What was the name of the supercontinent proposed in Continental Drift Theory?
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Study Notes
Plate Tectonics
- Earth's crust is divided into moving tectonic plates due to convection currents in the mantle.
- Alfred Wegener proposed the Continental Drift Theory in 1912, which laid the groundwork for plate tectonics.
- Continental Drift Theory suggests continents separate from a supercontinent, Pangaea.
Pangaea and Panthalassa
- Pangaea was the ancient supercontinent, surrounded by the Panthalassa ocean.
Tectonic Plates
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Primary Tectonic Plates:
- Pacific, North American, Antarctic, South American, African, Eurasian, Indian Australian.
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Secondary Tectonic Plates:
- Caribbean, Nazca, Cocos, Scotia, Arabian, Philippine, Juan de Fuca.
Types of Plate Movements
- Mantle Convection: Movement transfers heat from Earth's core to the lithosphere.
- Slab Pull (Convergent): Denser oceanic plates sink beneath lighter continental plates.
- Ridge Push (Divergent): Plates slide down the raised asthenosphere beneath mid-ocean ridges.
Plate Boundaries
- Convergent Boundaries (Destructive): Plates collide, creating subduction and causing earthquakes.
- Divergent Boundaries (Constructive): Plates move apart, allowing magma to rise and form new crust.
- Transform Boundaries (Conservative): Plates slide past each other horizontally without creating or destroying crust.
Earth's Internal Structure
- Seismic Waves help identify Earth's layers: S-Waves only travel through solids indicating solid vs. liquid layers.
- Rock Samples provide insights into the composition of Earth's layers.
- Major layers: Crust (0.5% of mass), Mantle (80% of mass), Core (15% of volume, comprised of solid inner core and liquid outer core).
Earthquake Fundamentals
- Earthquakes occur from the sudden release of energy, typically associated with faulting or rock breaking.
- Most earthquakes (90%) occur in the Pacific Ring of Fire, caused by convergent margins.
Fault Types
- Normal Fault: Tensional forces, shallow magnitude, found in divergent boundaries.
- Strike-Slip Fault: Shear forces, shallow/high magnitude, found in transform boundaries.
- Reverse Fault: Compressional forces, deep/high magnitude, found in convergent boundaries.
Elastic Rebound Theory
- Proposed by Harry Fielding Reid, explains energy release in earthquakes.
- The process involves friction, pressure, force, and energy.
Notable Earthquakes
- Chile Great Valdivian Earthquake: Noted for its extreme duration of 10 minutes.
- Philippines Luzon Earthquake: Occurred on July 16, 1990, with a magnitude of 7.8.
Seismic Wave Types
- Body Waves: Includes Primary (P-waves) and Secondary (S-waves); travels through Earth’s interior.
- Surface Waves: Travels through Earth's crust and causes the most damage during an earthquake.
Methods of Study
- Triangulation Method: Determines the epicenter of an earthquake using data from multiple seismic stations.
- Mohorovicic Discontinuity: Separates crust from mantle, discovered by Andrija Mohorovicic.
- Gutenberg Discontinuity: Separates mantle from the core, proposed by Beno Gutenberg.
Historical Context of Continental Drift
- Wegener based his theory on the resemblance of coastlines and fossils across continents.
- Major periods of geological history include the formation of Pangaea during the Permian period (250-300 million years ago).
Seafloor Spreading
- Describes the addition of new material to the ocean floor, driven by convection currents in the mantle.
- Evidence includes pillow-shaped rocks formed from rapid cooling of molten material at mid-ocean ridges.
- Mid-Ocean Ridge is the longest mountain range formed by divergent boundaries.
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Description
This quiz covers the fundamentals of plate tectonics, including the theory that Earth's crust is divided into plates and their constant movement influenced by convection currents in the mantle. It also discusses the historical context of the theory's discovery, particularly Alfred Wegener's Continental Drift Theory. Test your knowledge on these essential concepts of Earth science!
