Theories
What was the name of Alfred Wegner's Theory?
The Theory of Continental Drift
What do you call the boundary where two plates slide past each other in opposite directions?
Transform Boundary
Where do most earthquakes happen?
Around the Ring of Fire at transform and convergent boundaries
What is a volcano and where are they commonly found.
A volcano is a mountain that forms in Earth’s crust when molten material, or magma reaches the surface, they are commonly found along plate boundaries most commonly around the Pacific Plate in an area known as the Ring of Fire.
Which ocean is spreading?
The Atlantic Ocean
What evidence did Wegner's theory lack?
A way for the plates to move
The Mid-Atlantic Ridge is an example of this type of boundary where plates do what?
Divergent boundary where plates move away from each other
Describe what a tsunami is and how it is formed.
Tsunamis are giant waves that can be hundreds of feet high and move at speeds up to 500 miles an hour, they are created from the transfer of energy from an underwater earthquake into the ocean.
Name and describe the main parts of a volcano.
Magma chamber - a pocket of magma that collects beneath a volcano
Pipe - a long tube that extends from Earth’s crust up through the top of the volcano
Vent - an opening in a volcano through which molten rock and gases leave a volcano
Central/Main Vent - single vent at the top of the volcano
Side Vent - additional vents along the sides of a volcano
Lava Flow - the spread of lava as it pours out of a vent
Crater - a bowl-shaped area that may form at the top of a volcano, near its central vent
List and describe the layers of the Earth.
Crust - the outer most and thinnest layer on which we stand, solid
Asthenosphere - the softer section of the top of the Mantle which allows the plates to move
Mantle - largest section, solid
Outer Core - liquid layer of molten iron and nickel
Inner Layer - solid layer of extremely hot iron and nickel under high pressure from gravity
What was Henry Hess's theory and how did it save the Theory of Continental Drift?
The Theory of Sea Floor Spreading, which provided the mechanism for plate movement.
What type of boundary formed the Himalayan Mountain Range? (Be specific)
Convergent boundary of 2 continental plates
Who studies earthquakes and what instruments do they use?
Scientists who study earthquakes are called seismologists and they use seismographs to record seismic waves released by an earthquake to determine the earthquake's epicenter and they measure the magnitude of an earthquake using the Richter Scale
What are the three main types of volcanoes and how do geologists classify them?
The three main types are:
1) Cinder Cone Volcanoes
2) Composite or Stratovolcanoes
3) Shield Volcanoes
Classified based on four things:
height, shape, magma type, and eruption style
Explain what a hotspot is, how it works and provide a famous example.
A hotspot is an area where material from deep within Earth’s mantle rises to the crust and melts to form magma above which a volcano forms
Hotspots stay in one place while plates move over them
Famous examples include Hawaii and Yellowstone National Park
Wegner believed their had been one supercontinent 225 million years ago, what was its name, do scientists think there will ever be another one and why?
Pangaea was the name of Wegner's supercontinent and scientists think that there will be another supercontinent in the future based on the current position and movement of Earth's plates
Explain how the Rockies were formed, include the type of boundary (be specific)
The Rockies were formed when the oceanic Pacific Plate submerged at a shallow angle beneath the continental North American plate
Describe the Richter Scale, what is it used for and what do its numbers mean?
The Richter Scale is used to ascribe a single number to identify the magnitude of an earthquake, earthquakes measuring under a 5 cause little damage, earthquakes over 6 cause serious damage, and earthquakes over 8 are very rare, but cause the most damage.
Describe a shield volcano.
large, broad, gentle slope, resembles a warrior's shield, has low silica content and low viscosity and has quiet eruptions
Name and explain the 3 stages of a volcano's life and try to provide an example of each.
Active - has erupted at least once in the last 10,000 years
Dormant - has not erupted in the last 10,000 years, but is expected to erupt again (Mount Kilimanjaro)
Extinct - has not erupted in the last 10,000 years and is expected to never erupt again (Kohala)
What is the current theory regarding the movement of plates and what is it based off of?
The Theory of Plate Tectonics which combines The Theory of Continental Drift with The Theory of Sea Floor Spreading
Japan is an example of an island arc which is found above a trench formed at this type of boundary. Be specific
Convergent boundary of 2 oceanic plates
List and briefly describe the three main parts of an earthquake.
Focus - the area beneath Earth’s surface where rock that was under stress begins to break or move
Epicenter - the point on the surface directly above the focus
Seismic Waves - vibrations similar to sound waves, which travel through Earth carrying the energy released by an earthquake
Describe a Composite or Stratovolcano.
Steep - sided, symmetrical, medium sized compared to the others, magma and eruptions can vary creating layers, but typically magma is high in silica and has high viscosity, these volcanoes produce the most destructive explosive eruptions
Describe a Cinder Cone Volcano.
small, steep-sided, symmetrical, cone shaped, with high silica content and low viscosity producing explosive eruptions