Earth's Layers
The thinnest layer of the planet; can be either continental or oceanic
What is crust?
The scientist who came up with the theory of continental drift
Who is Alfred Wegener?
Where plates move apart; form volcanoes
The location where rock ruptures during an earthquake
The long pipe that magma travels up towards the surface of a volcano
What is a conduit?
Earth's thickest layer; made of igneous rocks; includes the lithosphere and the asthenosphere
What is the mantle?
The name Wegener gave to the single landmass the continents had once formed
What is Pangaea?
Where plates come together; sometimes form mountain chains
What is a convergent boundary?
Directly above the focus of an earthquake
What is the epicenter?
A type of volcano with steep sloping flanks that erupts thick, silica-rich lava
What is a composite volcano?
Made of iron and nickel; the innermost part of our planet
What is the core?
The reason Wegener's idea was not accepted
He could not explain how the continents moved
Where plates move horizontally past one another; produce earthquakes
What is a transform boundary?
The scale used for measuring the seismic waves of a earthquake
What is the Righter scale?
A type of volcano with gently sloping flanks that erupts runny lava and forms at hotspots
What is a shield volcano?
About 2200 km thick; creates Earth's magnetic field.
What is the outer core?
The process of forming new ocean crust by lava erupting at boundaries in the ocean floor
What is seafloor spreading?
Occurs when denser crust is pushed below less dense crust into the mantle, where it melts
What is subduction?
The rock below the fault
What is the foot wall?
A mixture of deadly gases, like sulfer dioxide and carbon monixide, and ash that races down the flanks of the volcano
What is pyroclastic flow?
About 1278 km in diameter; solid; under intense pressure and high heat
What is the inner core?
Shows the ages of rocks, and provided evidence that supported Wegener's theory
What is radiometric dating?
The type of boundary that formed the Himalayan Mountains
What is a convergent boundary?
A body wave that travels parallel to the direction of motion and is the fastest earthquake wave
What is a p-wave?
A large depression formed when a crater and the land around it collapse after an eruption
What is a caldera?