Layers of the Earth
This thin, cool outer layer of Earth makes up about 1% of Earth’s mass.
What is the crust?
This type of plate boundary occurs when plates move away from each other.
What is a divergent boundary?
Molten rock beneath Earth’s surface is called this.
What is magma?
Vibrations in the ground caused by movement along faults are called this.
What is an earthquake?
The large volcanic region around the Pacific Ocean where many earthquakes and volcanoes occur.
What is the Ring of Fire?
This extremely hot metallic layer makes up about 31% of Earth’s mass.
What is the core?
This process forms new oceanic crust at mid-ocean ridges.
What is seafloor spreading?
Molten rock that erupts onto Earth’s surface is called this.
What is lava?
The point inside Earth where rocks first move during an earthquake.
What is the focus?
The heat inside Earth mainly comes from the breakdown of these elements in the core.
What are radioactive elements?
This layer is hot plastic rock that makes up about 68% of Earth’s mass.
What is the mantle?
This force occurs when dense oceanic crust sinks into the mantle and pulls the rest of the plate behind it.
What is slab pull?
This type of volcano has gentle slopes and is common at hot spots like Hawaii.
What is a shield volcano?
The point on Earth’s surface directly above the focus.
What is the epicenter?
This heat transfer process moves mantle material in a cycle and drives plate movement.
What is convection?
This rigid layer made of crust and upper mantle forms tectonic plates.
What is the lithosphere?
This type of boundary occurs when plates slide past each other horizontally.
What is a transform boundary?
These large, steep-sided volcanoes form at convergent plate boundaries.
What are composite volcanoes?
The fastest seismic waves that arrive first at a seismometer.
What are P-waves?
This scale measures earthquake magnitude based on ground shaking.
What is the Richter scale?
This soft, plastic layer beneath the lithosphere allows tectonic plates to move.
What is the asthenosphere?
This heat-driven circular movement in the mantle helps move tectonic plates.
What are convection currents?
The speed and style of an eruption are affected by the lava’s silica content and this property describing how thick it is.
What is viscosity?
Scientists use at least three seismometers in this process to locate an earthquake’s epicenter.
What is triangulation?
The slow, rolling seismic waves that cause the most damage at Earth’s surface.
What are surface waves?