Plate Tectonics
What is the name of the theory that explains plate movement?
Plate tectonics.
What happens at a divergent boundary?
Plates move apart, creating new crust (e.g., at mid-ocean ridges).
What is the name for molten rock beneath the Earth's surface?
Magma.
What is the name of the instrument used to measure earthquakes?
A seismometer (or seismograph).
What is the outermost layer of the Earth called?
The crust.
What natural disaster often causes tsunamis?
Earthquakes under the ocean.
What are the two main types of tectonic plates?
Oceanic plates and continental plates.
What type of plate boundary creates mountains?
Convergent boundaries (where plates collide).
What is the difference between magma and lava?
Magma is molten rock beneath the surface; lava is molten rock on the surface.
What is the point on the Earth's surface above the earthquake’s focus?
The epicenter.
What are the four layers of the Earth?
The crust, mantle, outer core, and inner core.
What happens to the water level before a tsunami hits?
The water recedes dramatically from the shore, exposing the seafloor.
Name one example of a transform boundary (use map).
The Pacific Plate.
Name one example of a transform boundary.
The San Andreas Fault in California.
Name one type of volcano.
Shield volcanoes, stratovolcanoes, or cinder cone volcanoes (any one is correct).
What is the scale used to measure earthquake magnitude?
The Richter scale (or Moment Magnitude Scale, for more modern terminology).
Which layer of the Earth is made of liquid iron and nickel?
The outer core.
Why do tsunamis grow larger as they approach land?
Tsunamis slow down and their wave height increases as they approach shallow coastal waters.
How do convection currents in the mantle cause plate movement?
Convection currents in the mantle move molten rock, pushing plates apart or pulling them together.
What is the difference between oceanic and continental plate collisions?
Oceanic plates subduct under continental plates because oceanic plates are denser.
Why are some volcanoes more explosive than others?
Explosiveness depends on the magma’s silica content and viscosity; higher silica makes magma thicker and traps gases.
What causes earthquakes to happen at transform boundaries?
Transform boundaries cause plates to slide past each other, releasing energy as stress builds up.
Why is the mantle important for tectonic plate movement?
The mantle’s convection currents drive plate tectonics.
Name one early warning sign of a tsunami.
A sudden retreat of water, strong shaking from an earthquake, or unusual animal behavior (e.g., animals fleeing).
How many major tectonic plates are there on Earth (use map)?
There are seven major tectonic plates.
Why are subduction zones important in plate tectonics?
Subduction zones recycle crust and generate magma, forming volcanic arcs and trenches.
What is the "Ring of Fire," and why is it significant?
The "Ring of Fire" is a tectonic zone around the Pacific Ocean where many earthquakes and volcanoes occur due to subduction.
What is a fault line, and why is it important in studying earthquakes?
A fault line is a crack in the Earth's crust where movement occurs; it marks boundaries between moving plates.
What evidence suggests the Earth's core is made of iron and nickel?
Seismic wave studies (S-waves don’t travel through liquid, and the behavior of P-waves suggests a dense, metallic core).
How does the depth of the ocean floor affect the speed of a tsunami wave?
Shallower water slows the wave down, compressing energy into a smaller space, making it taller and more destructive.