Tectonic Plates
The Earth's outer layer is broken into these large pieces.
What are tectonic plates?
Melted rock beneath Earth's surface.
What is Magma?
The place on Earth's surface directly above the earthquake focus.
What is the epicenter?
This instrument records the shaking of the ground during an earthquake.
What is a seismograph?
A wide, gently sloping volcano formed from low viscosity lava.
What is a shield volcano?
This boundary forms when plates move apart.
What is a divergent boundary?
What is lava?
The point underground where an earthquake begins.
What is the focus?
These are the fastest seismic waves and the first to be detected by instruments.
What are P-waves?
A small, steep sided volcano formed from explosive eruptions of ash and rock.
What is a cinder cone volcano?
This type of plate boundary is associated with the formation of volcanoes, as magma rises through the gap created by plates moving apart.
What is a divergent boundary?
A bowl shaped area that forms around a volcanoes main vent.
What is a crater?
This scale is used today to measure the total energy released by an earthquake.
What is the Mercalli Scale?
This type of wave moves through solids and liquids and is slower than P-waves.
What are S waves?
A tall, cone shaped volcano made from alternating layers of lava and ash.
What is a composite volcano?
The process in which one tectonic plate is forced under another at a convergent boundary.
What is subduction?
A fast moving current of hot gas and volcanic material.
What is a Pyroclastic Flow?
The boundary where two tectonic plates slide past each other.
What is a transform boundary?
A large amount of these are often used around active volcanoes to monitor seismic activity and tremors.
What are seismometers?
A large, collapsed volcanic crater formed after a massive eruption that empties the magma chamber beneath it.
What is a caldera?
The volcanic island chain of the Hawaiian Islands was formed as the Pacific Plate moved over this geological feature.
What is a hotspot?
A massive eruption that causes the volcano to collapse can create this large depression.
What is a caldera?
This is the fault type where two plates slide past each other horizontally, often causing earthquakes.
What is a strike-slip fault?
This scale is used to classify volcanic eruptions based on their volume of erupted materials.
What is the Volcanic Explosivity Index (VEI)
A type of volcano that forms when thick lava piles up near the vent instead of flowing far.
What is a lava dome?