Volcanoes happen at which plate boundaries
Convergent and divergent
Earthquakes happen at which plate boundaries
Convergent and transform
Describe oceanic crust
Dense, thin, underwater
What determines how plates interact with each other
The kind of boundary and which way the plates are moving
Show me the charades for p-waves, s-waves, and surface waves
What does the magnitude of an earthquake measure
the energy released by an earthquake
What is a strike-slip fault?
Two walls slide past each other at a transform boundary, San Andres Fault is an example
Happens at ocean trenches, one denser plate converges under another
What is subduction?
Magma flows through the cracks in the crust creating mid-ocean ridges, older rock is farther away
Sea-floor spreading
Describe convection currents
Magma heats up next to the inner core and rises toward the mantle, then it cools and sinks back down.
Boiling water or a lava lamp
What happens if the magma has low silica
It will have a quiet eruption, the lava will be thin and runny
How does a normal fault create a mountain?
The hanging wall slips down creating a valley, and the footwall becomes a mountain
Name and describe the three types of stress
compression- pushing
tension- pulling
shearing- pushing in two different directions
how did fossils show the theory of continential drift
fossils were found on many continents, plant fossils were found on 5 continents
What is the difference between lava and magma?
Lava is molten rock that is above the Earth's surface. Magma is molten rock that has not exited the crust yet.
How is a shield volcano formed?
A hot spot slowly leaks steady eruptions and builds up over a broad area
describe how ocean floor uplift can cause a tsunami
One oceanic plate is pushed into another plate, overtime the stress causes it to buckle and pop up. This displaces the ocean water and causes a tsunami.
When two continental plates converge, a _____ forms. When two oceanic plates converge, a _____ forms. When an oceanic plate collides with a continental plate, _____ can form.
Mountain range
Volcano
Volcanic mountains
How were the Himilayas formed?
The Indian contentinal plate and the Eurasian Plate collided when Pangea broke apart. They are the youngest mountains in the world at 40 million years old.
How was Iceland formed?
The mid ocean ridge released so much molten rock that the volcanic island Iceland formed. Iceland has many rift valleys and several small volcanoes.
Name and describe the two types of volcanic eruptions
explosive- High volumes of silica, gases are trapped, lava/ash/bombs explode high into the air
quiet- low volumes of silica, gases can escape, lava emerges slowly
A fold in a plate can arch upward into a ____. It can also arch downward into a ____. These together create rolling mountains/hills.
Anticlines
Synclines
What is the Theory of Plate Tectonics?
The Earth's lithosphere is broken up into plates that move and interact
What is the Theory of Continental Drift?
Alfred Wegner developed the theory that once all the conteninents were fused together but they drifted apart over time
What type of volcano is Yellowstone National Park?
It was a super volcano, but after it erupted last time it became a caldera, a collapsed volcano