Lessons 4 and 5 Vocabulary
“Plotting Earthquakes” and
“Using Earthquakes to Study the
Earth’s Interior”
Lesson 4
Plate boundary – A place where pieces of the
broken lithosphere meet. Boundary types
includes convergent, divergent, and transform.
Ring of Fire – A zone of intense earthquake and
volcanic activity that encircles the Pacific Ocean
basin; also called the Circum-Pacific Belt.
Lesson 4 Continued
Intensity – A measure of the damage done by
an earthquake. Determined on the basis of the
earthquake’s effect on people, structures, and
the natural environment.
Magnitude – A measure of the total amount of
energy released at the focus of an earthquake.
Lesson 5
Asthenosphere – The layer of the mantle that lies
directly below the lithosphere and flows, like taffy.
Core – sting of a liquid iron outer core and a solid
iron-nickel inner core. See also crust; mantle.
Crust – The earth’s outer layer; the coolest and
least dense layer of the earth. See also core;
mantle.
Lesson 5 Continued
Lithosphere – the cool, solid outer shell of the earth. It
consists of the crust and the rigid uppermost part of the
mantle and is broken up into segments, or plates.
Mantle – the layer of the earth beneath the crust. It is about
2900 km thick, and it makes up about 83 percent of the
earth’s interior. See also core; crust.
Plate tectonics – A theory that the lithosphere is broken into
segments, or plates, that “float” on the asthenosphere, and
that interactions among these plates are associated with
earthquakes and volcanic activity and form mid-ocean ridges,
trenches, mountains, and chains of volcanic islands