asthenosphere
The “plastic” (semisolid) layer of Earth
below the
lithosphere; part of
the upper mantle
convection current
The movement of
the mantle, which
pushes the plates
around
core
the iron-and-nickel
center of Earth
crust
the outermost shell
of the Earth; the
upper part of the
lithosphere
inner core
the innermost part
of the Earth; solid
nickel and iron
lithosphere
the solid, outermost
shell of the Earth
includes the crust
and upper mantle
mantle
the thick layer of
Earth between the
crust and the core
outer core
the liquid portion of
the core
plates
one of the 15 major
segments that make
up Earth’s
lithosphere
Continental Drift
A theory proposed
by Alfred Wegner
which states the
continents are
moving away from
each other
convergent
boundary
boundary between
2 plates moving
together
boundaries
between two plates
divergent boundary
that are moving
apart
fault
a fracture in the
Earth’s crust
A chain of volcanic
mountains that are
Mid-Atlantic Ridge the site of seafloor
spreading under the
Atlantic Ocean
Plate Tectonics
Theory
the theory that the
outer part of the
earth is made up of
rigid plates that
move relative to
each other
Seafloor Spreading
the process by which
oceanic plates diverge
(move apart) allowing
magma to fill the void
and create a new
seafloor
subduction
a type of
convergent
boundary where a
plate slides
underneath another
plate
transform
boundary
boundary where
the plates move
past each other in
opposite directions
earthquake
a sudden trembling of
the Earth caused by the
abrupt release of energy
caused by plate
movement. Common
around plate boundaries
and faults
epicenter
the point on the
Earth’s surface
directly above the
focus of an
earthquake
focus
the point of origin
of an earthquake
seismic waves
waves generated by
an earthquake in all
directions
seismograph
an instrument that
detects, records,
and measures
vibrations
produced by
earthquakes
seismologists
scientists who
study earthquakes
hot spots
a very hot area
underneath the crust. As
a plate slowly passes
above it, magma melts
the crust creating chains
of volcanoes
lava
molten rock on the
surface of the Earth
magma
molten rock
underground
ring of fire
many volcanoes and
earthquakes
happen where
plates meet around
the Pacific Ocean
shield volcano
a large, broad, and
flat type of volcano
stratovolcano
a steep sided
volcano
viscosity
the thickness or
thinness of lava or
magma
fossils
the remains or
imprints in rock of
things that lived
long ago
a timeline that
represents the
entire history of the
geologic time scale
Earth since its
formation
geology
the study of the
Earth
pangea
the name of the one
huge continent that
means “all lands”