Structure of the Earth
This is the thin, brittle outer layer of the Earth where we live.
What is the crust?
This type of plate boundary occurs when two plates move away from each other.
What is constructive (divergent) boundary?
Molten rock beneath the Earth’s surface is called this.
What is magma?
This instrument is used to measure earthquakes.
What is a seismometer?
One positive impact of volcanoes is that they create this type of soil.
What is fertile soil?
This thick layer sits beneath the crust and allows tectonic plates to move.
What is the mantle?
This plate boundary involves plates sliding past each other, causing earthquakes.
What is a conservative (transform) boundary?
This volcanic hazard is a fast‑moving flow of hot gas, ash, and rock.
What is pyroclastic flow?
This scale measures the magnitude, or energy released, by an earthquake.
What is the richter scale?
This 2004 earthquake and tsunami devastated countries around the Indian Ocean.
What is the Sumatra-Andaman Earthquake?
The Earth’s core is extremely hot and is made mostly of these two metals.
What are iron and nickel?
At this boundary, the denser oceanic plate sinks beneath the continental plate.
What is a destructive (convergent) boundary?
A lahar is best described as this type of volcanic hazard.
What is a fast moving mud flow?
The point inside the Earth where an earthquake starts is called this.
What is the focus?
This type of hazard happens immediately during a volcanic eruption.
What is a primary hazard?
This part of the Earth stores energy that can be released during earthquakes.
What is the crust (or brittle rocks on the crust?)
The process that creates new oceanic crust at constructive boundaries is called this.
What is sea-floor spreading?
This volcanic hazard caused massive destruction in Colombia in 1985 at Nevado del Ruiz.
What is a lahar?
The point on the Earth’s surface directly above the focus is known as this.
What is the epicenter?
Long‑term effects like famine and disease are known as these hazards.
What is a tertiary hazard?
The crust and upper mantle together are known as this rigid layer.
What is the lithosphere?
The San Andreas Fault is an example of this type of plate boundary.
What is a conservative (transform) boundary?
This volcanic eruption in 1815 caused “the year without a summer.”
What is Mount Tambora?
A magnitude 8 earthquake is this many times stronger than a magnitude 7.
What is 10x stronger?
This factor often determines why earthquakes cause more damage in poorer countries.
What is vulnerability (or quality of buildings / levels of development)?