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Volcanoes: Glossary

A

a'a
lava with a rough surface
Algae
an aquatic plant
Ancient
a time in history that no longer exists

B

beneficial
good
boundaries
the edges of the plates where they come together
Bulbous
a swollen bubble - puffed out
Bulging
to protrude as in a bump

C

central vent
the main opening of a volcano
Cinder
material blown out of the volcano that has cools before it falls
cinder volcano
volcano made largely from cinders
composite volcano
volcano made of layers of cooled lava flows
Conic
cone shaped
continents
one of seven main land masses on the earth
convection
the transfer of heat by movement
Crater
a cup shaped depression or opening in a volcano
Crust
outer layer of the earth’s surface
Crystals
a clear mineral formation made of flat sides

D

Dormant
no longer active

E

earthquakes
vibrations of the earth’s surface
Erosion
process that wears away the earth’s surface
Erupt
the movement of material from inside a volcano to the outside
Expand
to make larger
Extinct
no longer living

F

Frothy
foamy or full of air

G

gas bubbles
bubbles formed when gasses get trapped
Geologic
related to the earth and its construction
Geysers
steam and hot water that spews from the earth
Gravity
the natural law that causes objects to be attracted to each other

H

heat resistant
protects against heat
hot spots
areas in the mantle where rocks melt
hydrothermal
related to hot water

I

Inactive
not active
inhabited
where people live
inner core
solid layer of the earth made of iron
intolerable
living things cannot survive under this condition

J

jet stream
a wind on the earth that moves west to east and is the major source of weather movement

L

laboratories
a place where scientific studies or experiments take place
Lava
melted rock that has escaped onto the outside of the crust
lava dome
a bulge of lava that never flows

M

Magma
melted rock that is inside of the earth
magma chamber
location where the magma sits before it erupts - also known as magma reservoir
magma reservoir
location where the magma sits before it erupts - also known as magma chamber
magnetic field
region of space around the earth affected by the magnetic force within the earth
Mantle
layer of the earth between the crust and the outer core where magma moves from heat

O

observatory
a place where scientists study volcanoes
outer core
area inside the earth between the inner core and the mantle

P

pahoehoe
smooth lava with wrinkle and twists
Pangaea
original continent in earth’s history
pillow lava
lava that erupts under water and cools quickly
poisonous chemical
gases that are dangerous to life
Predict
tell in advance
prehistoric
before humans were around to record the event
pressure
a pushing force
pyroclastic flow
a cloud of ash, dust and other debris along with gas erupting from a volcano

R

Ring of Fire
boundary of tectonic plates along the Pacific Ocean - majority of earthquakes and volcanoes take place here
Rotates
turns
Rupture
a broken place

S

secondary vent
a vent which branches off the central vent of a volcano
shield volcano
a large volcano spread out over the ground - fairly flat rather than mountain-like
solar system
the sun, planets and other space bodies nearby

T

tectonic plates
plates that make up the earth’s crust

V

Vent
an opening in the earth’s surface
viscosity
the property that causes a liquid to flow
volcanologist
scientist who studies volcanoes

W

weathering
the process that breaks down rocks
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